According to the present invention, a plasma processing apparatus includes an analysis unit that obtains wavelengths of the light correlated with a plasma processing result, selects, from the obtained wavelengths, a wavelength having a first factor that represents a deviation in an intensity distribution of the light and is larger than a first predetermined value, and predicts the plasma processing result using the selected wavelength, or an analysis unit that obtains values computed using each of light intensities of a plurality of wavelengths and correlated with the plasma processing result, selects, from the obtained values, a value having a second factor that represents a deviation in a distribution of the obtained values and is larger than a second predetermined value, and predicts the plasma processing result using the selected value.