<p>Using a cloth (6) between a metal electrode (2) and the body surface of a subject as a capacitance, a biometric sensor (1) is touched to the body surface through capacitive coupling, a bioelectric signal is extracted from the metal electrode (2), and an electrocardiographic waveform is outputted using an impedance converter having a high input impedance and a low output impedance from the out put of the biometric sensor (1).</p>
