In an acoustic image generation apparatus with a probe having an ultrasonic transducer, providing a scanning length setting part that sets a target scanning length in a scanning process of the probe, a coordinate obtaining part that sequentially obtains a coordinate of the probe in real space, a scanned length calculation part that calculates a scanned length based on the coordinate obtained by the coordinate obtaining part, a progress level display generation part that generates a progress level display that indicates progress of the scanning process based on the target scanning length and the scanned length, and a display part that displays the progress level display.