Semiconductor device

A plurality of the same kind of npn-type bipolar transistors are disposed regularly on a semiconductor layer that is provided over an insulation layer. The plurality of unit bipolar transistors are connected in parallel, thereby to form a plurality of desired bipolar transistors. A deep trench isolation surrounds a group of or the whole of the plurality of unit bipolar transistors that are connected in parallel, for a plurality of desired bipolar transistor that require thermal stability.