An SOI type pressure sensor has been developed which can measure pressure at high temperature environments above 150°C.SOI stands for Silicon On Insulator. A single-crystalline silicon layer is located on an insulating layer formed on a silicon substrate. The piezoresistors of the SOI type pressure sensor are made from the single-crystalline silicon layer which is isolated from the silicon substrate by the insulating layer. There is no leakage current from the piezoresistors. The SOI structure is made by the laser-recrystallization-method.The properties of the SOI type pressure senor are as good as conventional semiconductor pressure sensors.