Abstract: An apparatus that acquires information on an object includes an element that converts an acoustic wave propagating from the object through a holding member into a reception signal at an element position and an information processor that uses the reception signal to generate characteristic information on the object. The information processor determines, for each unit region of the object, whether the unit region is a unit region for numerical analysis in which the delay time of the acoustic wave is acquired by numerical analysis, or a unit region for interpolation in which the delay time is acquired by interpolation processing; performs numerical analysis on the unit region for numerical analysis.