According to one embodiment, a plasma processing-apparatus processing object support platform includes a lower plate, an upper plate, and a variable condenser. The lower plate is electrically conductive. The upper plate is provided on the lower plate. A processing object is placed on an upper surface of the upper plate. The variable condenser is provided along a circumferential direction of the lower plate in a region at an upper outer circumferential vicinity of the lower plate. The region has an annular configuration. The variable condenser includes a first capacitance element and a second capacitance element disposed respectively on an inner circumferential side and an outer circumferential side in the region having the annular configuration. Mutually-different control voltages are suppliable to the first capacitance element and the second capacitance element.