An ultrasonic endoscope (12, 212) comprising: a laminated body (47, 247) that comprises an ultrasonic transducer array (50, 250) in which a plurality of ultrasonic transducers are arranged, and a backing material layer (52, 252) that supports the plurality of ultrasonic transducers; a cable portion (70, 79, 82, 85) that comprises a plurality of cables each of which is electrically connected to a corresponding one of the plurality of ultrasonic transducers, and a shield member that covers the plurality of cables from outside and that is made of a metal; and a first heat conductive member (62, 262) that is disposed on a side surface of the laminated body (47, 247), wherein the first heat conductive member (62, 262) is extended to the shield member that is grounded to a housing and is thermally connected to the shield member; a first insulation tube that covers the cable portion; an electroconductive connection pipe that covers a part of the first insulation tube on a proximal end side of the ultrasonic endoscope; a second insulation tube that is connected to one end of the connection pipe on the proximal end side and that covers a part of the connection pipe and a part of the first insulation tube on the proximal end side of the ultrasonic endoscope; and a second heat conductive member (80, 81, 83) that is disposed in contact with both of the first insulation tube and the connection pipe. a laminated body (47, 247) that comprises an ultrasonic transducer array (50, 250) in which a plurality of ultrasonic transducers are arranged, and a backing material layer (52, 252) that supports the plurality of ultrasonic transducers; an ultrasonic transducer array (50, 250) in which a plurality of ultrasonic transducers are arranged, and a backing material layer (52, 252) that supports the plurality of ultrasonic transducers; a cable portion (70, 79, 82, 85) that comprises a plurality of cables each of which is electrically connected to a corresponding one of the plurality of ultrasonic transducers, and a shield member that covers the plurality of cables from outside and that is made of a metal; and a plurality of cables each of which is electrically connected to a corresponding one of the plurality of ultrasonic transducers, and a shield member that covers the plurality of cables from outside and that is made of a metal; and a first heat conductive member (62, 262) that is disposed on a side surface of the laminated body (47, 247), wherein the first heat conductive member (62, 262) is extended to the shield member that is grounded to a housing and is thermally connected to the shield member; a first insulation tube that covers the cable portion; an electroconductive connection pipe that covers a part of the first insulation tube on a proximal end side of the ultrasonic endoscope; a second insulation tube that is connected to one end of the connection pipe on the proximal end side and that covers a part of the connection pipe and a part of the first insulation tube on the proximal end side of the ultrasonic endoscope; and a second heat conductive member (80, 81, 83) that is disposed in contact with both of the first insulation tube and the connection pipe.