A plasma processing apparatus capable of achieving a uniform plasma space therein is provided. The plasma processing apparatus includes a processing vessel, a mounting table, a shield member, a shutter for an opening configured to be moved up and down, a first driving unit and a second driving unit. The processing vessel has a sidewall, and the sidewall is provided with a transfer path through which a processing target object is carried-in/carried-out. The mounting table is provided within the processing vessel. The shield member is provided along an inner surface of the sidewall to surround the mounting table and provided with an opening facing the transfer path. The first driving unit is configured to move the shutter up and down. The second driving unit is configured to move the shutter in a forward-backward direction with respect to the shield member.