An object information acquiring apparatus is employed which includes elements each receiving a photoacoustic wave from a region of interest of an object and outputting an electric signal, a probe that supports the elements such that directional axes of the elements are gathered, and that holds an acoustic matching member, a scanner that moves the probe, a controller, and a processor that generates image data on the region of interest. The controller performs, on the same region of interest, photoacoustic measurements in which the probe is moved along a curved trajectory, with the elements each allowed to receive a photoacoustic wave, and moves the probe in the same rotating direction as direction of the curved trajectory at a time between the photoacoustic measurements.
