A motor drive apparatus and an air-conditioner using the motor control apparatus of the invention has a feature to be able to gradually increase the dc voltage value (Ed) to a predetermined value when starting the switching operation of a chopper circuit by means of the dc voltage control means thereof, and when stopping the switching operation of the chopper circuit to be able to gradually decrease the dc voltage value (Ed) to a predetermined value. Further, the dc voltage command value (Ed*) is adjusted so as to be able to maintain a preferred value of dc voltage. Thereby, fluctuation in the number of revolutions of the motor (N) can be prevented even if the converter is started or stopped while the motor is operating, thereby allowing the motor drive apparatus and air-conditioner using the motor control apparatus of the invention to be operated at their maximum capacities.