Patent ID: 7488288

Claim:
An ultrasonic endoscope, comprising: an insertion portion comprising a distal hard portion including an endoscopic observation unit having at least an illumination section and an observation section at its distal end surface, and an electronic scanning type of ultrasonic observation unit fitted on an outer circumferential section of the endoscopic observation unit, wherein the ultrasonic observation unit includes an ultrasonic transducer array having a plurality of ultrasonic transducers arranged cylindrically or circularly, and a backing layer cylindrically formed on an inner circumferential surface of the ultrasonic transducer array; and a flexible circuit board, arranged between the ultrasonic transducer array and the backing layer, on which is formed a plurality of first terminals each directly connected to an electrode of a respective one of the ultrasonic transducers, a plurality of second terminals to which cables are respectively directly connected, and wiring patterns respectively formed between the first terminals and the second terminals to directly connect the first terminals and the second terminals, wherein the flexible circuit board has a stepped structure having a large-diameter section on which the first terminals are formed on an external surface side, a small-diameter section on which the second terminals are formed on an external surface side, and an annular support section formed on an inner circumferential side of the small-diameter section.