A photoacoustic microscope includes a light source, an objective lens, a light scanner, a photoacoustic wave detector, and a calculation unit. The light source emits excitation light. The objective lens focuses the excitation light within a specimen. The light scanner scans the specimen with the excitation light. The photoacoustic wave detector detects photoacoustic waves. The calculation unit uses a correlation coefficient to calculate a shift in waveform due to a change over time in photoacoustic waves between a standard position and a calculation position. The calculation unit calculates the depth from the standard position at the calculation position based on the shift.