An ultrasound endoscope having an ultrasound probe that is provided at a rigid portion at a distal end of an insertion portion, a cable that transmits electrical signals to and from the ultrasound probe, and a rigid flexible substrate that is interposed between the ultrasound probe and the cable to transmit the electrical signals, and configures a part of a planar member in which a plurality of layers including a wiring layer are stacked as a flexible portion further including an insulating layer, and the other portion as a rigid portion further including a rigid layer, wherein the ultrasound probe is connected to the rigid portion, and at least a part of the flexible portion is disposed in a spiral shape to surround a wiring connection portion of the cable and the rigid flexible substrate, and an uncovered portion of a distal end side of the cable.