An apparatus for manufacturing a non-circular coil, includes a pair of swinging pieces, an operation piece to be inserted and removed from between the distal ends of the pair of swinging pieces to increase or reduce the distance between the distal ends of the pair of swinging pieces, and a winding mechanism for winding a wire around an outer circumference of a distal end of the pair of swinging pieces so as to form a non-circular coil, wherein side surfaces of the operation piece, which avoid contact with the pair of swinging pieces, bulge outward to be curved and are formed so as to be continuous with outer circumferential surfaces of the pair of swinging pieces, around which the wire is wound, in a state in which the operation piece is inserted between the distal ends of the pair of swinging pieces.