PURPOSE: To mold fans of different shapes inexpensively by a method wherein the mold for a fan is composed of four segmental metal blocks and a part of the blocks are changed to the separate ones when molding a fan with a partially different shape.

CONSTITUTION: The metal mold for a resin fan is composed of four segmental blocks of the pair of metal blocks 8a, 9a for molding a group of blades and the pair of metal blocks 8b, 10a for molding the fan boss 2a. When a fan with the small diameter D2 for the boss hole 3a is desired to be provided besides a fan with the large diameter D1 for the boss hole 3a of the fan boss 2a, it can be obtained by changing the pair of metal blocks 8b, 10a for molding the fan boss with the pair of metal blocks 8c, 10b for molding another fan boss.