An acoustic wave detector detects photoacoustic waves generated by absorbing measurement light emitted toward a subject, and reflected acoustic waves with respect to acoustic waves transmitted toward the subject. A preamplifier amplifies a detection signal output by the acoustic wave detector. A bypass unit is intended to output the detection signal without passing through the preamplifier. Controller causes the preamplifier to enter an operating state and selects a first path along which the detection signal is amplified by the preamplifier and then is input to the reception circuit as a signal path in a case where the photoacoustic waves are detected. The controller stops an amplification operation in the preamplifier and selects a second path along which the detection signal is input to the reception circuit via a bypass unit as the signal path in a case where reflected acoustic waves are detected.