PURPOSE: To prevent the generation of a punched dreg in the case of punching out process by a press and improve the yield of a material by forming a wave part by bending plural places along the peripheral direction in a thickness direction and arranging recessed parts and projected parts alternately across the entire periphery of a ring main body.

CONSTITUTION: A wave spring 1 is arranged between the return spring 103 and a clutch disc 104 in a transmission 100 in a vehicle. The ring main body 2 of this wave spring 1 is formed by the welding and connection at the welded part 21 of both ends of a wire rod wound in a ring shape. A wave part 3 is formed on this ring main body 2 and in this wave part 3, recessed parts 31 and projected parts 32 are alternately arranged across the entire periphery of the ring main body 2 by bending plural places along its peripheral direction in a thickness direction. Thereby, the generation of a punched dreg in the case of punching out process by a press is prevented and the yield of a material can be improved.