A plasma processing device includes: a chamber; a flat-plate-shaped first electrode; a first high frequency power supply; a helical second electrode disposed outside the chamber and disposed to face the first electrode with a quartz plate forming an upper lid of the chamber therebetween; and a gas introducing unit, in which a second high frequency power supply and a third high frequency power supply are configured to be electrically connected to the second electrode, the second high frequency power supply being configured to apply an AC voltage of a second frequency to the second electrode, the third high frequency power supply being configured to apply an AC voltage of a third frequency to the second electrode, and the third frequency being higher than the second frequency; and two types of AC voltages are configured to be simultaneously applied.