In a plasma processing apparatus, insulating members are horizontally and separately arranged above a mounting unit in a processing chamber. Each insulating member serves as a partition between a vacuum atmosphere in the processing chamber and an external atmosphere of the processing chamber. Antennas are provided on the respective insulating members to generate an inductively coupled plasma. A first processing gas is supplied into the processing chamber and adsorbed onto a substrate on the mounting unit. A second processing gas is turned into a plasma by power supplied from the antennas and is supplied to activate the first processing gas adsorbed onto the substrate or react with the first processing gas adsorbed onto the substrate. The supply of the first processing gas and the supply of the second processing gas are alternately repeated multiple times with a process of evacuating an inside of the processing chamber interposed therebetween.