WE CLAIM:
1. A semiconductor device, comprising:
a substrate;
a source electrode, a drain electrode, and a gate electrode;
a semiconductor layer in contact with said source electrode and said drain electrode;
a gate insulating layer insulating said semiconductor layer from said gate electrode; and
a second insulating layer in contact with said semiconductor layer on the opposite side of said semiconductor layer from said gate insulating layer;
wherein said semiconductor layer contains a carbon nanotube;
wherein said second insulating layer contains an electron-donating material having one or more selected from a nitrogen atom and a phosphorus atom; and
wherein said second insulating layer has an oxygen permeability of 4.0 cc/(m2-24h-atm) or less.
2. The semiconductor device according to claim 1, wherein said second insulating layer further comprises a polymer compound having one or more structures selected from the group consisting of a hydroxy group, cyano group, fluoro group, chloro group, and amide bond.
3. The semiconductor device according to claim 2, wherein said polymer compound is a vinyl alcohol resin.
4. The semiconductor device according to claim 1, wherein said second insulating layer comprises at least a first layer provided nearer to said semiconductor layer and a second layer provided farther from said semiconductor layer,
wherein said first layer contains said electron-donating material, and
wherein said second layer has an oxygen permeability of 4.0 cc/(m2-24h-atm) or

less.
5. The semiconductor device according to claim 4, wherein said second layer
■ comprises a polymer compound having one or more structures selected from the group consisting of a hydroxy group, cyano group, fluoro group, chloro group, and amide bond.
6. The semiconductor device according to claim 5, wherein said polymer compound contained in said second layer is a vinyl alcohol resin.
7. The semiconductor device according to any one of claims 4 to 6, wherein a difference, in absolute value, in solubility parameter between the material constituting said first layer and the material constituting said second layer is 5.0 (MPa)1/2 or more.
8. The semiconductor device according to any one of claims 1 to 7, wherein said electron-donating material is a compound having a nitrogen atom.
9. The semiconductor device according to any one of claims 1 to 8, wherein said electron-donating material is a compound containing a ring structure containing a nitrogen atom.
10. The semiconductor device according to any one of claims 1 to 9, wherein said electron-donating material is one or more compounds selected from an amidine compound and a guanidine compound.
11. The semiconductor device according to any one of claims 1 to 10, wherein said second insulating layer has a film thickness of 100 urn or less.
12. The semiconductor device according to any one of claims 1 to 11, wherein said second insulating layer has a water vapor permeability of 20 g/(m2-24h) or less.
13. The semiconductor device according to any one of claims 1 to 12, comprising a protective layer in contact with said second insulating layer on the opposite side of said second insulating layer from said gate electrode, wherein said protective layer has a water vapor permeability of 20 g/(m2-24h) or less.

14. The semiconductor device according to any one of claims 1 to 13, wherein said carbon nanotube exists as a carbon nanotube composite in which a conjugated polymer is attached to at least a part of the surface of said carbon nanotube.
15. A complementary semiconductor device, comprising: an n-type semiconductor device containing said semiconductor device according to any one of claims 1 to 14; and a p-type semiconductor device.
.16. The complementary semiconductor device according to claim 15, wherein said p-type semiconductor device comprises:
a substrate;
a source electrode, a drain electrode, and a gate electrode;
a semiconductor layer in contact with said source electrode and said drain electrode; and
a gate insulating layer insulating said semiconductor layer from said gate insulating layer;
wherein said semiconductor layer of said p-type semiconductor device contains a carbon nanotube.
17. The complementary semiconductor device according to claim 16, wherein said p-type semiconductor device comprises a second insulating layer in contact with said semiconductor layer of said p-type semiconductor device on the opposite side of said semiconductor layer of said p-type semiconductor device from said gate insulating layer of said p-type semiconductor device.
18. The complementary semiconductor device according to claim 17, wherein at least part of said second insulating layer of said p-type semiconductor device is constituted by the same material as said second layer of said second insulating layer of said n-type semiconductor device.
19. The complementary semiconductor device according to claim 17 or 18, comprising a protective layer in contact with said second insulating layer of said p-

type semiconductor device on the opposite side of said second insulating layer from said gate insulating layer, wherein the material used for said protective layer of said p-type semiconductor device is the same as used for said protective layer of said n-type semiconductor device, and wherein said protective layer of said p-type semiconductor device has a water vapor permeability of 20 g/(m2-24h) or less.
20. A method of producing said semiconductor device according to any one of claims 1 to 14, said method comprising the step of forming said second insulating layer by a coating method.
21. The method of producing a semiconductor device according to claim 20, wherein said method is a method of producing said semiconductor device according lo any one of claims 1 Lo 14, ,
wherein said second insulating layer comprises at least a first layer provided nearer to said semiconductor layer and a second layer provided farther from said semiconductor layer,
wherein said first layer contains said electron-donating material, and
wherein said second layer has an oxygen permeability of 4.0 cc/(m2-24h-atm) or less;
wherein said method comprises the steps of:
forming said first layer by a coating method; and
forming said second layer by a coating method,
wherein a drying temperature used in forming said second layer is equal to or lower than the glass transition temperature of said first layer.
22. A wireless communication device, comprising at least said semiconductor
. device according to any one of claims 1 to 14 and an antenna.
23. A wireless communication device, comprising at least said complementary semiconductor device according to any one of claims 15 to 19 and an antenna.
24. A merchandise tag, comprising said wireless communication device according

to claim 22 or 23.