An external ultrasonic probe includes a transducer array including multiple transducers arranged along an azimuth direction, the multiple transducers transmitting and receiving ultrasonic waves; and a covering material having a projecting surface touchable with a living body, formed of a single member, covering an entire front-surface side of the transducer array, and covering at least a part of a side-surface side of the transducer array. In a section dividing a width of the transducer array in the azimuth direction substantially into two equal parts, a width between two points on the projecting surface falling down from a top of the projecting surface by 2 mm is larger than a width of the transducer array in an elevation direction. A difference between the width between the two points and the width of the transducer array in the elevation direction is 5 mm or less.