Plasma processing device

The present invention provides a plasma processing device including a vacuum container that has controllable internal pressure, gas supply means, an electrode that is provided in the vacuum container and has an upper surface on which a substrate is placed, and an antenna that is arranged to face the electrode to form inductive coupling, in which the antenna that is configured to form the inductive coupling includes one end connected to a high-frequency power source via a matching circuit, and the other end that is an open end, a length of the antenna is less than ½λ of a wavelength (λ) of an RF frequency, an impedance adjustment circuit connected in parallel to the antenna is connected to an RF feeding side of the antenna, and a reactance component of a combined impedance by the impedance adjustment circuit is adjustable from a capacitive load to an inductive load with respect to the RF frequency supplied to the antenna.