In radio frequency power source devices for delivering AC voltage outputs in antiphase with each other, having a configuration to divide the voltage output from a radio frequency output circuit into two, it is not possible to perform switching as appropriate, between different voltage values, high voltage and low voltage, resulting in that the voltage at an output end is reduced to have a half peak value of the voltage output of the radio frequency output circuit. There is provided a radio frequency power source device configured to change a voltage ratio between two output end voltages, by switching a connection state of a voltage divider that divides the radio frequency voltage, in such a manner that the radio frequency voltage is divided into voltage outputs in antiphase with each other with respect to ground potential, and high voltage and low voltage are delivered in switching manner. Switching of the connection state in the voltage divider enables selective delivery of voltage having different values, high voltage or low voltage, and by selecting and delivering high voltage for the time high voltage is required, reduction of the voltage output from the radio frequency output circuit is prevented.