A response signal generating unit (3) applies a predetermined supply signal (2S) to a detection element (1) and outputs, as a response signal (3S), a signal which has changed in accordance with the impedance of an object (10) with which the unit is in contact through the detection element (1). A waveform information detection unit (4) detects waveform information corresponding to the impedance of the object (10) on the basis of the response signal (3S) from the response signal generating unit (3), and outputs a detection signal (4S) representing the waveform information. A biometric recognition unit (5) determines on the basis of the detection signal (4S) from the waveform information detection unit (4) whether or not the object (10) is a living body.