Abstract: The present invention aims to provide a novel detonation flame spray apparatus which makes it possible to attain stable detonation flame spraying while using a hydrogen fuel. In the detonation flame spray apparatus, stable pulsed detonation with short DDTL has been attained by oppositely injecting hydrogen and oxygen while separating a sub-combustion room and a main combustion room to which a spiral ridge is formed at an inner wall. In addition, by distributing supply ports of flammable gas to the sub-combustion room and a rear end of the main combustion room, high frequency operation can be realized while assuring necessary heat amounts for fusing flame spray material and a mechanism for supplying intermittently the flame spray material to together with the hydrogen fuel has realized enhancement of flame spraying efficiency.