An information acquisition apparatus according to the present invention includes a container configured to store a deformable acoustic matching member, a receiving unit configured to receive an acoustic wave generated from an object and output a signal, and a processing unit configured to acquire object information based on the signal. The processing unit acquires sound speed information about the object, acquires sound speed information about the acoustic matching member, acquires positional information about the acoustic matching member, acquires propagation time information about the acoustic wave between an interesting position of the object and the receiving unit using the positional information, the sound speed information about the object, and the sound speed information about the acoustic matching member, and acquires the object information about the interesting position using the signal and the propagation time information.
