A body-cavity-insertion-type probe wherein an electronic circuit board is provided via a relay board on a back surface side of an oscillator unit. A backing member is joined to a center region of a back surface of the electronic circuit board. A wiring sheet is joined to a peripheral region of the back surface. A rear wing and a front wing of the wiring sheet surround a backing case, and a right wing and a left wing of an exhaust heat sheet protrude outward via two slits formed in a heat dissipation shell and are fixed on an outer surface of the heat dissipation shell. Heat generated by the electronic circuit board is transmitted to the heat dissipation shell via the exhaust heat sheet or the backing case, and heat is dissipated by the heat dissipation shell as a whole.
