PURPOSE: To apply mold releasing agent automatically without dispersing spray mist by a method wherein after molding tools are clamped and the space between them is filled with the mold releasing agent, the agent is exhausted and the coat of the mold releasing agent is stuck to the inner surface of the tools.

CONSTITUTION: As the rim molding tool (a) is clamped, the valve 19 is opened. The cavity between molds is filled with mold releasing agent through the valve 19 to adhere the surface of the top force 11 and the bottom force 12 to furnish the coating of the mold releasing agent. Then, after the mold releasing agent is exhausted from the valve 19, the molds are opened, the excessive mold releasing agent adhered to the top force core 11 and the bottom force cavity 12 is wiped off and the molds are clamped again to shot resin material.