To provide a method for cleaning a reused pat in high reliability, capable of efficiently removing a deposit while suppressing the use of a chemical agent to the utmost.

A deposit is gradually accumulated on the reutilized part of every kind placed in a film forming chamber (the so-called bell jar or reaction tube) along with a wafer in a membrane forming process in the production of a semiconductor device and it is necessary to periodically remove the deposit. In the cleaning method for removing this deposit, the outermost surface deteriorated layer of the deposit bonded to the reutilized part is removed at first by atmospheric pressure plasma treatment 1 and organic matter is removed by next wahing treatment 2. Next, the main deposit is removed by high pressure jet cleaning treatment 3 using pure water and, subsequently, the reutilized part is cleaned by ultrasonic cleaning treatment 4 using a solution containing a surfactant while ultrasonic waves with a predetermined frequency or more are applied to the reutilized part. The surfactant is removed by next pure water washing treatment 5 and followed by drying treatment 6.