An ultrasonic diagnostic apparatus characterized by comprising: an ultrasonic probe having a laminated structure including an acoustic matching layer, a transducer layer comprising a plurality of arrayed transducers, and a backing layer, wherein at least one of the acoustic matching layers has a non-segmented structure; a transmission/reception unit configured to transmit and receive ultrasonic waves to and from an object via the transducers; an image generation unit configured to generate image data based on an output from the transmission/reception unit; a control unit configured to control the transmission/reception unit to synchronize ultrasonic-wave generation by a specific transducer of the plurality of transducers with ultrasonic-wave reception by a transducer of the plurality of transducers that is different from the specific transducer, and wherein said specific transducer is configured to generate ultrasonic waves of a frequency lower than the frequencies of the ultrasonic waves transmitted to an object to image the object; and wherein the acoustic matching layer with the non-segmented structure converts the ultrasonic waves generated by the specific transducer into transverse waves, the apparatus further comprising a phase shift detection unit configured to detect a phase shift between an output signal from the transmission/reception unit and a reference signal, the output signal corresponding to synchronization between the ultrasonic-wave generation by the specific transducer and the ultrasonic-wave reception of said transverse waves wherein the transverse waves have a resonance frequency of the acoustic matching layer with the non-segmented structure. an ultrasonic probe having a laminated structure including an acoustic matching layer, a transducer layer comprising a plurality of arrayed transducers, and a backing layer, wherein at least one of the acoustic matching layers has a non-segmented structure; a transmission/reception unit configured to transmit and receive ultrasonic waves to and from an object via the transducers; an image generation unit configured to generate image data based on an output from the transmission/reception unit; a control unit configured to control the transmission/reception unit to synchronize ultrasonic-wave generation by a specific transducer of the plurality of transducers with ultrasonic-wave reception by a transducer of the plurality of transducers that is different from the specific transducer, and wherein said specific transducer is configured to generate ultrasonic waves of a frequency lower than the frequencies of the ultrasonic waves transmitted to an object to image the object; and wherein the acoustic matching layer with the non-segmented structure converts the ultrasonic waves generated by the specific transducer into transverse waves, the apparatus further comprising a phase shift detection unit configured to detect a phase shift between an output signal from the transmission/reception unit and a reference signal, the output signal corresponding to synchronization between the ultrasonic-wave generation by the specific transducer and the ultrasonic-wave reception of said transverse waves wherein the transverse waves have a resonance frequency of the acoustic matching layer with the non-segmented structure.