A plasma processing apparatus has a vacuum vessel, a processing chamber arranged in the vacuum vessel and supplied with gas, a support electrode arranged in the processing chamber to support an object to be processed, a radio frequency providing unit for supplying a radio frequency in UHF or VHF band, and a magnetic field generating unit for generating a magnetic field in the processing chamber, wherein the radio frequency providing unit includes an antenna having a groove or step formed in its surface opposing the process object, whereby plasma of high density and high uniformity can be generated in a wide parameter region.