A coil spring manufacturing device includes a mandrel around which a wire is wound, a feed mechanism which feeds the wire toward the mandrel, guide members which guide the wire, a chuck which fixes a distal end of the wire, and a clamp mechanism. The clamp mechanism sandwiches the wire from both sides before the distal end of the wire reaches the mandrel. Further, the clamp mechanism can be rotated about a fulcrum by rotation actuator, and can also be slid in a direction along an axis of the mandrel by sliding actuator. In a state in which the wire is sandwiched by the clamp mechanism, the clamp mechanism is rotated, and if necessary, is slid. Thereby, a bent portion for a negative pitch portion of a coil spring is formed at a part of the wire.