According to one embodiment, an ultrasonic probe (11) has a laminated structure of a non-segmented acoustic matching layer, transducer layer with arrayed transducers, and backing layer. A transmission/reception unit (20) transmits and receives ultrasonic waves to and from an object via the transducers. A control unit (39) controls the transmission/reception unit (20) to synchronize ultrasonic-wave generation by a specific transducer of the transducers with ultrasonic-wave reception by a different transducer. A phase shift detection unit (27) detects a phase shift between an output signal from the transmission/reception unit (20) and a reference signal, the output signal corresponding to synchronization between the ultrasonic-wave generation and the ultrasonic-wave reception. A temperature estimation unit (29) estimates the temperature of the acoustic matching layer based on the dependence of the phase shift on the temperature of the acoustic matching layer.
