An ultrasonic probe includes a probe main body section; and a curved extending section which is extended in a state of curving relative to the probe main body section toward a first intersecting direction side. The curved extending section includes a first curved outer surface facing the first intersecting direction side, and a second curved outer surface facing a second intersecting direction side. A first curve start position at which the first curved outer surface starts curving relative to the longitudinal axis toward the first intersecting direction side is positioned on the distal side with respect to a second curve start position at which the second curved outer surface starts curving relative to the longitudinal axis toward the first intersecting direction side.