A motor control device includes a control condition storage unit storing at least one of a control condition defined by an equivalent voltage supplied to a three-phase motor and a control condition defined by relationship between the equivalent voltage supplied to the three-phase motor and a frequency of PWM signal, a control condition extracting unit extracting the control condition from the control condition storage unit in response to a temperature of a viscous fluid supplied by a pump having the three-phase motor as a power source, and a PWM controlling unit controlling a switching element included in an inverter circuit based on a PWM signal related to the extracted control condition when the three-phase motor is started.