The processing device includes: a temperature transition acquisition unit that acquires rising transition of the temperature of the winding in a state in which a first voltage is applied in order to raise a temperature of the winding to a first temperature and further acquires falling transition of the temperature of the winding in a state in which a second voltage is applied in order to lower the temperature of the winding to a second temperature that is lower than the first temperature after the temperature of the winding converges to the first temperature; and a decision unit that calculates stator-related parameters on the basis of the falling transition to decide a stator temperature characteristic mode and further calculates winding-related parameters on the basis of the rising transition and a stator temperature characteristic model to decide a winding temperature characteristic model.