Aluminum alloy-made piston 1 is provided having, on external circumferential surfaces of both skirt portions 8, 9 of base member 1a, a multilayer solid lubricant coating film including inner coating film 21 and outer coating film 22. Both of the inner and outer coating films contain at least one of polyimide-imide resins, polyimide resins and epoxy resins as a binder resin. The inner coating film is formed of a material containing graphite etc. as a solid lubricant, and applied to the external surfaces of the skirt portions and then irradiated with laser beams by a laser heating apparatus at a temperature rise rate of 11.3-23.9° C./sec. for 10 seconds to be dried. Then, the outer coating film is applied to the top surface thereof, followed by baking treatment. With this, the multilayer solid lubricant coating film is formed in a possibly short total treatment time in a coating film-forming step.