To enable smooth engagement of a clutch that forms several wedge- shaped spaces by several circumferential cam faces formed on an outside surface of inner ring and by raceway surfaces formed on an inside surface of outer ring to store a roller energized to a narrower direction of the wedge-shaped space inside each space without using a jig when the outer ring is worked into a temporary assembly comprising the inner ring and the roller.

An inclined guide face 15 is formed on an end part of the raceway surface 3 of the outer ring 1 to be worked later into the temporary assembly comprising the inner ring 2 and the roller 8. A corner part 13 of the roller 8 in a free state is abutted on the guide face 15. A component of force according to an inclination of the cam face 4 is made to arise from a force applied to the roller 8 from the guide face 15, which moves the roller 8 to a wider direction of the wedge-shaped space 5 to diminish an outside diameter of circumscribed circle of the roller 8.