A subject information acquisition apparatus comprises a light emission unit configured to emit a pulse beam onto a subject in response to an emission trigger； an acoustic wave probe configured to receive an acoustic wave generated in an interior of the subject in response to emission of the pulse beam, and convert the received acoustic wave into an electric signal； a conversion unit configured to convert the electric signal into digital data； a clock generation unit configured to generate a sampling clock used to drive the conversion unit； an image generation unit that generates an image representing information relating to the interior of the subject on the basis of the digital data； and a synchronization unit that synchronizes the sampling clock with the emission trigger input into the light emission unit.
