Patent attributes
A plasma processing apparatus comprises an upper electrode 42, a lower electrode, a grounding member 61 provided above the upper electrode 42 via an insulating member 60; and a DC power supply for applying a DC voltage to the upper electrode 42. Gas diffusion rooms 54 and 55 communicating with a gas supply opening 53 formed at a lower surface of the upper electrode 42 are formed in the upper electrode 42 and a gas flow path 62 communicating with the gas diffusion rooms 54 and 55 is formed in the insulating member 60. A bent portion 63 for allowing a gas within the gas flow path to flow in a direction having at least a horizontal component is formed at the gas flow path 62 such that an end of the gas flow path 62 cannot be seen from the other end thereof when viewed from the top.