PURPOSE: To provide a manufacture of PC plates having finely finished surfaces and being prevented from surface separation by powerful adhesion.

CONSTITUTION: Into the mold frame, 10-50 pts.wt. clinker powder and high fluidial mortar are flowed, each containing 50wt.% or more calcium aluminate compound 5-50wt.% represented by 11 CaO.7Al2O3.CaX2 (X denotes halogen element) or 3CaO.3Al2O3.CaSO4 or 12CaO.7Al2O3, and containing gypsum powder at a rate of 50wt.% with respect to 100 pts.wt. portland cement, and concrete is then placed to be hardened and mold-released subsequently.