To provide a superheated steam treatment apparatus capable of efficiently treating an object by superheated steam containing a high concentration of hydroxyl radicals. The superheated steam treatment apparatus includes an induction heating unit 4 configured to generate superheated steam by induction heating saturated stream, a treatment chamber 5 configured to allow the superheated steam generated by the induction heating unit 4 to be introduced thereinto, and a discharge treatment unit 6 located in the treatment chamber 5 and configured to treat the introduced superheated steam by discharge. The discharge treatment unit 6 has a frame serving as a support for the discharge treatment unit, a discharge electrode located at an upper part of the frame, a mesh-like opposite electrode located below the discharge electrode, and a high-frequency power source configured to supply high-frequency, high-voltage power between the discharge electrode and the opposite electrode to cause the discharge, whereby an object immediately below the opposite electrode is allowed to be treated by the superheated steam having an increased hydroxyl radical concentration due to the discharge.