A novel chamber cleaning method using atomic hydrogen is proposed. A heated tungsten wire is used as a catalyzer to obtain atomic hydrogen from hydrogen molecular gas, and this atomic hydrogen is used for chamber cleaning, removing amorphous silicon (a-Si:H) and polycrystalline silicon (poly-Si) films deposited on chamber walls. High rates of etching of a-Si:H (250 nm /min), poly-Si (190 nm/min) and crystalline silicon (100 nm/min) are obtained.