Patent ID: 8203859

Claim:
A high frequency device for supplying a high frequency power to a load, the high frequency device comprising: an oscillator that varies an oscillation frequency; a high frequency power supplier that serves as a power source by amplifying an oscillation signal output from the oscillator for supplying the high frequency power to the load; a reflected-wave information calculator that calculates reflected wave information on a reflected wave power, and outputs the reflected wave information; a frequency controller that controls the oscillation frequency of the oscillator so as to lower the reflected wave information; an impedance adjuster that is positioned downstream of the high frequency power supplier in a power supplying direction, and that includes at least one controllable variable reactance element; and an element controller that controls the controllable variable reactance element of the impedance adjuster so as to lower the reflected wave information, wherein: the element controller starts controlling the controllable variable reactance element when the reflected wave information has not become smaller than a reference value by controlling, by the frequency controller, the oscillation frequency of the oscillator so as to lower the reflected wave information, the frequency controller does not control the oscillation frequency of the oscillator while the element controller controls the controllable variable reactance element, the load includes a plasma processing device, and the frequency controller varies the oscillation frequency of the oscillator so as to reduce the reflected wave information after the plasma processing device starts discharging, and the frequency controller varies the oscillation frequency of the oscillator so as to reduce the reflected wave information after the plasma processing device starts discharging and before the plasma processing device stops discharging.