A vertical plasma processing apparatus for a semiconductor process for performing a plasma process on target substrates all together includes an exciting mechanism configured to turn at least part of a process gas into plasma. The exciting mechanism includes first and second electrodes provided to a plasma generation box and facing each other with a plasma generation area interposed therebetween, and an RF power supply configured to supply an RF power for plasma generation to the first and second electrodes and including first and second output terminals serving as grounded and non-grounded terminals, respectively. A switching mechanism is configured to switch between a first state where the first and second electrodes are connected to the first and second output terminals, respectively, and a second state where the first and second electrodes are connected to the second and first output terminals, respectively.