The microwave plasma processing apparatus includes a power feeding rod that applies high frequency wave for RF bias, the upper end of which is connected to a susceptor, and the lower end of which is connected to a high frequency output terminal of a matcher in a matching unit; a cylindrical external conductor that encloses around the power feeding rod serving as an internal conductor; and a coaxial line. The coaxial line is installed with a choke mechanism configured to block undesired microwave that enters the line from a plasma producing space in a chamber, and leakage of the microwave to an RF feeding line is prevented in the middle of the line, thereby suppressing the microwave leakage.