There is provided a ultrasonic motion detecting device that detects a three-dimensional motion of an object. The ultrasonic motion detecting device, comprises first and second ultrasonic transducers 13 having piezoelectric elements arranged in an array, which transmit ultrasonic waves to an object and acquire reflection signals from the object, a motion detection unit 20 that extracts an estimation region which is used for estimating a motion of the object from the reflection signals that are acquired by the first and second ultrasonic transducers, and detects a three-dimensional motion within the estimation region, and an image display unit 19 that displays the three-dimensional motion within the estimation region, wherein ultrasonic wave scanning surfaces due to the first and second ultrasonic transducers cross over each other.
