An ultrasonic probe according to an embodiment includes a receiving unit and a light emitting unit. The receiving unit receives input operation related to transmission and reception of ultrasonic waves performed by a piezoelectric vibrator transmitting and receiving ultrasonic waves under the control of an apparatus body. The light emitting unit emits light in a first light emission state when connected to the apparatus body and emits light in a second light emission state when the receiving unit receives input operation in a state that the light emitting unit is connected to the apparatus body.