To stabilize detection accuracy and improve reliability by accurately positioning a temperature sensitive resistor and a drilled hole formed on both surfaces of a silicon substrate.

The front surface 1A side of a silicon substrate 1 is provided with a diaphragm portion 4 using a part of an insulating film 2 by forming a drilled hole 9 from the rear surface 1B side. When the diaphragm portion 4 is formed, an injection portion of high concentration ion is previously formed at a position corresponding to the diaphragm portion 4 of the front surface 1A side of the silicon substrate 1. An anisotropic etching groove portion 10 in the drilled hole 9 is formed in a crystalline anisotropic etching process, then an isotropic etching process is selectively applied to the ion injection portion from the bottom side, and thereby, an isotropic selection etching groove portion 11 is formed. Thus, a temperature sensitive resistor 6 and the diaphragm portion 4 can be accurately positioned.