A temperature prediction device includes an application voltage specifying unit which specifics a voltage value applied to an electromagnetic coil based on a distance from a distance detection unit provided in the electromagnetic coil to an output shaft, a coil current detection unit which detects a current value flowing when a voltage is applied to the electromagnetic coil on the basis of the voltage value specified by the application voltage specifying unit, and a coil temperature estimation unit which estimates a temperature of the electromagnetic coil on the basis of the voltage value specified by the application voltage specifying unit, the current value detected by the coil current detection unit, and a relational expression between the voltage value applied to the electromagnetic coil, the current value flowing when a voltage is applied to the electromagnet coil on the basis of the voltage value applied to the electromagnetic coil, and the temperature of the electromagnetic coil.