In a MOS type semiconductor device, a source region, a channel region and a drain region of a MOS type device are arranged on the same plane, while a gate electrode is also arranged on the same plane adjacent to the channel region. Another set of a source region, a channel region, and a drain region may also be arranged on the same plane, and the latter MOS device is arranged adjacent to the gate electrode. This type of device may be constructed as a CMOS type device. In another type of semiconductor device, the above-mentioned type plane arrangement of the source, channel, and drain regions are layered via an insulator layer, while a gate electrode is provided vertically so as to be adjacent to the two channel regions.