PURPOSE: To form a timing pulley having a high accuracy without wasting a material, by forming a metallic plate to a bottomed cylindrical body, fitting and fixing an inside jig to which a tooth form has been formed, to a cylindrical part and pressing a gear cutting die against the outside periphery of the cylindrical part, rotating both of them, and forming the tooth form the cylindrical part.

CONSTITUTION: A metallic plate is formed to a bottomed cylindrical body 1 by drawing it by a press, etc., and a pulley base material 4 in which a cylindrical part is a belt stretching part, and bottom plate 3 is a supporting part is formed. Subsequently, an inside jig 6 which has formed a tooth part 5 having an outside diameter of almost the same diameter as an inside diameter of the cylindrical part 2 and having a pitch corresponding to a tooth of a timing pulley derived in the axial direction, on its outside peripheral surface is fitted to the cylindrical part 2, and the pulley base material 4 and the inside jig 6 are fixed by a clamper 7. Next, a gear cutting die 9 which has formed a tooth part 8 is pressed against the outside periphery of the cylindrical part 2 of the pulley base material 4, so that tooth part of the gear cutting die 9 is engaged to the tooth part 5 of the inside jig 6, and by rotating both of them by the same pitch, a timing pulley 11 which has formed a tooth form 10 on the pulley base material 4 is formed.