A plasma processing apparatus includes a control device and configured to plasmarize a gas supplied to an interior of a processing container to perform a plasma processing on an object to be processed, wherein the control device includes: a measurer configured to measure an electron energy distribution function of plasma in the interior of the processing container, and a parameter changer configured to change parameters relating to the plasma processing so that the electron energy distribution function measured by the measurer during the plasma processing approaches a target electron energy distribution function.