An Ultrasonic Equipment and its Catheter-type Ultrasonic Probe can be inserted in capillaries such as blood vessels, and comprises a catheter-type ultrasonic probe for generating ultrasonic waves by a piezoelectric transducer arrayed at its tip. A plurality of the piezoelectric transducer segments are arrayed on a two-dimensional plane, perpendicular or approximately perpendicular to the insertion direction of the probe into a capillary with their ultrasonic wave emitting surface faced in the insertion direction. A part of the plane is cut out to provide a guide unit for passing a treating catheter or a guide wire in the insertion direction.