PURPOSE: To miniaturize the titled device by a method wherein it is constructed in such a manner that the difference between the resistance temperature coefficient and the sensitivity temperature coefficient of a strain gauge formed on the main surface of an Si single crystal substrate becomes nearly equal to the temperature coefficient of the parallel resistor of a differential amplifier.

CONSTITUTION: When the resistance values of diffused gauges 21∼24 are all set equal Rg, the resistance variations caused by pressure of strain gauges 21 and 23+ΔR, that of strain gauges 22 and 24-ΔR, the resistance values of resistors 81 and 82 parallel-connected to an operational amplifier 5 both Rf, a power source voltage VS, an output voltage Vo led out to an output terminal 61 is expressed by the equation I . When the applied pressure is P, and the pressure sensitivity of a bridge circuit is K, the equation II holes. When the resistance temperature coefficient of the gauges 21∼24 is αg, sensitivity temperature coefficient βg, and the former coefficient of the parallel resistors 81 and 82 αf, they are approximated as expressed by the equation III. In other words, the temperature coefficient of the output voltage Vo becomes (αf-αg+βg), and therefore selection of the relation that the difference between αg and βg equals to αf enables the output voltage Vo of the operational amplifier 5 to obtain excellent characteristics without temperature dependence.