In a medical imaging apparatus for imaging mammary gland and breast while compressing the breast with a compression plate, the posture of an ultrasonic probe relative to the compression plate is kept constant and the moving motion of the ultrasonic probe is stabilized. The apparatus includes: an imaging stage; a compression plate; an ultrasonic probe provided to maintain acoustic connection to the compression plate, for transmitting ultrasonic waves according to drive signals and receiving ultrasonic echoes to output reception signals; an ultrasonic imaging unit for supplying the drive signals to the ultrasonic probe and generating image data based on the reception signals; a detecting unit for detecting a location and/or a posture of the ultrasonic probe relative to the compression plate; and a control unit for controlling the location and/or the posture of the ultrasonic probe based on a detection result of the detecting unit.