An ultrasonic endoscope in which the temperature rise can be suppressed with a reduced diameter. The ultrasonic endoscope includes: an ultrasonic transducer part including plural ultrasonic transducers; an exterior member for accommodating the ultrasonic transducer part; and a heat conducting part provided inside of the exterior member and respectively connected to the ultrasonic transducer part and an inner surface of the exterior member. It is preferable that the heat conducting part has a coefficient of thermal conductivity equal to or more than 10 W/(m·K). Further, it is preferable that one of the heat conducting member and the exterior member has an electric insulation property.