An object information acquiring apparatus includes: a light source that generates a first light beam； a receiving unit that includes an irradiating unit emitting the first light beam so as to be directed to a predetermined optical focusing region and an acoustic wave detecting unit detecting a first acoustic wave generated when the first light beam is emitted to an object； a scanning unit that performs relative movement between the object and the receiving unit so that the receiving unit follows a concave or convex shape of a surface of the object while the first light beam is emitted and the first acoustic wave is detected； and an acquiring unit that acquires characteristics information on the optical focusing region of the object based on a detection result obtained by the acoustic wave detecting unit.
