A process lubricant constituting an optimal compound of oil-soluble surface-active reagents in high-viscosity mineral oil supplemented with organic downstream products Presence of significant amount of oil-soluble surface-active reagents allows to create a firm separating film on the surface of a mould, which assures easy removal of the product after autoclave curing without adherence of concrete to the surface of moulds. The grease is distinguished by high adhearing capacity on the vertical surfaces and assures reliable protection of steel moulds from corroision, which significantly reduces moulds maintenance costs. Owing to its viscosity characteristics and absense of electric filter plugging the grease can be used at modern import automatized cellular concrete production lines.