PURPOSE: To provide anti-corrosion surface processing treatment forming a thick coating layer having a smooth and beautiful surface, imparting long-term anti-corrosion properties, facilitating the treatment of an uneven surface, enabling rapid treatment in large-scaled work and enabling the execution on the spot.

CONSTITUTION: A preparation process preheating the surface α of a matrix to proper temp. by a gas burner 2, a main process ejecting a plastic powder P to the heated surface from a jet nozzle 3 to apply and form a plastic powder deposited layer on the heated surface and a finish process spraying hot air on the plastic powder layer from a spray orifice 7 to melt the same to form a smooth surface are continuously and consistently performed.