To obtain a solid lubricant coating liquid which can impart lubricating properties and mold release to existing sliding heat-resistant components and to molds required to have mold release, etc., to make them serviceable even under atmospheric high-temperature or a vacuum high-temperature conditions by mixing a solid lubricant and a binder in water under agitation.

At least one powdery solid lubricant selected among boron nitride, graphite, tungsten disulfide and molybdenum disulfide and a binder comprising powdery mica and water glass are added in water under agitation. The content of the solid lubricant is desirably 5-55wt.% based on the coating fluid. The ratio of the binder to the solid lubricant is 5-98vol.%. The mica is powdery and desirably has a mean particle size of 1-3μm. When the coating fluid is heat-treated, the water is evaporated, and the solid lubricant is solidified with the binder to form a coating film on the surface of a base material.