PURPOSE: To facilitate the judgment on the replacement of an adhesive pad by reporting the replacement timing of the adhesive pad.

CONSTITUTION: Electrodes 3a, 3b are fitted to a human body, when the adhesive strength of an adhesive pad is reduced and the voltage Vx becomes V1 or above and V2 or below, an input terminal I1 becomes an L-level, and an input terminal I2 becomes an H-level. When the input terminal I1 is an L-level and the input terminal I2 is an H--level, a pulse is outputted from the output terminal O2 of a control circuit l, a reporting circuit 5 is driven, and the replacement timing of the adhesive pad due to the reduction of the adhesive strength of the adhesive pad is reported to a user via a light emitting diode or a buzzer.