A processing unit calculates first displacement related information concerning a first direction of an object to be measured by using data in either one of an increase period and a decrease period of a force applied to the objected to be measured, among first received data received by a first ultrasonic probe. In addition, the processing unit calculates second displacement related information concerning a second direction of the object to be measured by using data in the same period as that used to calculate the first displacement related information, among second received data received by a second ultrasonic probe.
