An apparatus for forming an amorphous coating film by jetting flame containing particles of a flame spray material from a flame spray gun toward a base material, causing the particles to be melted by the flame, and cooling both the particles and the flame with the means of a cooling gas before they reach the base material. The apparatus includes a tubular member provided among the path along which the flame is jetted that it surrounds the flame passing through a melting zone in which the particles are melted. The tubular member has a flow channel for the cooling gas, formed along and integrally to the tubular member.