PURPOSE: To enable accurate detection of breakage of a stuck part of a sensor chip by comparing a potential difference generated across both ends of a gauge resistance with a comparison voltage generated from a comparison voltage generator connected in parallel to a feeder circuit.

CONSTITUTION: A sensor 1 has a comparison voltage generator 5 connected in parallel to an amplifier 4, a voltage comparator 6 and a disorder signal output circuit 7. When a stuck part of a sensor chip breaks for one reason or another, a gauge resistance 2 causes various disorders (breakage). In any case, under such a state of disorder, a higher potential difference Vg as compared with that at a normal time is generated across both ends of the resistance 2. The potential difference Vg is compared 6 with a comparison voltage Vr to be generated from the voltage generator 5. When the comparator 6 detects the potential difference Vg exceeding the voltage Vr, a signal output circuit 7 outputs a voltage lower than a power source voltage to a disorder signal terminal 9 as logical 0. Thus, the voltage Vr is set properly with the voltage generator 5 beforehand thereby enabling the detection of any disorder state of a resistance 2.