There is provided a plasma processing apparatus, including: a chamber main body; a plasma trap installed inside a chamber provided by the chamber main body, and configured to divide the chamber into a first space and a second space; a mounting table installed in the second space; a plasma source configured to excite gases supplied to the first space; and a potential adjustment part including an electrode to be capacitively coupled to a plasma generated in the first space, and configured to adjust a potential of the plasma.