To provide a coating method of a releasing agent capable of uniformly coating the releasing agent on a surface of a cavity having a complicated shape.

A releasing agent is formed into mist by compressed air blown from a blower (30). The releasing agent mist is allowed to flow in the forward direction to a releasing agent feed passage (20), a cavity (7) and a releasing agent returning passage (40). In this condition, the releasing agent mist to be discharged from the releasing agent returning passage (40) is accumulated in a releasing agent mist accumulation tank (46) in a pressure-accumulated state. By changing a solenoid directional selector valve (29), the releasing agent mist accumulated in the pressure-accumulated state is allowed to flow in the reverse direction to the releasing agent returning passage (40), the cavity (7) and the releasing agent feed passage (20). This reciprocal coating operation is repeated at least one time. Thus, the releasing agent can be uniformly coated on the surface of the cavity (7) having the complicated shape.