A coating method through HVOF spraying that comprises generating a combustion jet in a combustion chamber connected to one end of a barrel while controlling the temperature of the combustion jet by supply of an inert gas to the jet, feeding resin coating materials into the temperature-controlled combustion jet and leading them to pass through the barrel, and spouting the coating particles through a spout port along with the combustion jet therethrough to thereby coat the substrate surface; wherein the length of the barrel, the temperature of the combustion jet and the physical properties of the coating particles are defined so as to satisfy both the following formulae (1) and (2). Numerical ⁢ ⁢ Formula ⁢ ⁢ 1 α × t r > 0.5 ( 1 ) Numerical ⁢ ⁢ Formula ⁢ ⁢ 2 2.5