A constant velocity universal joint includes outer and inner joint members that transmit torque while allowing angular displacement via balls, a power transmission shaft connected to the inner joint member in a torque transmittable manner, and a detachable mechanism between the inner joint member and the power transmission shaft to detach the power transmission shaft from the inner joint member. The detachable mechanism includes a cylindrical member externally fit onto the power transmission shaft, spheres movable in a radial direction in the cylindrical member, and an annular member movable in an axial direction on an outer periphery of the cylindrical member. Locking claws are provided at an end of an inner joint member side of the annular member, and a locking groove is provided at an end of an annular member side of the inner joint member. The locking claws are fitted into the locking groove.