A transistor is provided, which is entirely and partially transparent by the use of a transparent channel layer made of zinc oxide or the like. A channel layer
formed of a transparent semiconductor such as zinc oxide ZnO. A transparent electrode is used for all of a source
, a drain
and a gate
, or a part of them. As the transparent electrode, a transparent conductive material such as conductive ZnO doped with, for example, group III elements is used. As a gate insulating layer
, a transparent insulative material such as insulative ZnO doped with elements capable of taking a valence of one as a valence number or group V elements is used. If a substrate
must be transparent, for example, glass, sapphire, plastic or the like can be used as a transparent material.