In a manufacturing process of a semiconductor device by forming a structure film on a substrate in a reaction chamber of a manufacturing apparatus, cleaning inside the reaction chamber is performed. That is, a precoat film made of a silicon nitride film containing boron is deposited on an inner wall of the reaction chamber, a silicon nitride film not containing boron is formed as the structure film on the substrate in the reaction chamber, and the inner wall of the reaction chamber is dry etched to be cleaned. At this time, the dry etching is terminated after boron is detected in a gas exhausted from the reaction chamber.