PURPOSE: To obtain an operation always stable by allowing the circuit to be reset when a power supply voltage of a system has increased to an optional prescribed value so as to avoid the use without notifying malfunction.

CONSTITUTION: A booster circuit 1 boosts a device power supply V and a constant voltage generating circuit 2 generates a constant voltage B higher than the device power supply voltage V from the boosted voltage A. The constant voltage B is compared with the device power supply voltage V by a comparator 3, and when the device power supply voltage V is increased more than the constant voltage B, an output of the comparator 3 is inverted so as to apply reset to a main section 4 of the integrated circuit device. The use of this device makes it possible to know the possibility of malfunction due to the increase of the device power supply voltage V in advance and the possibility of the use of erroneous result without notice is precluded in this way. The power supply voltage V generating the said reset signal is set to an optional prescribed value from the correlation with the constant voltage B, and the operation stable at all times is obtained.