The present invention relates a low power control device using a sleep timer, and more particularly, to a low power control device using a controllable sleep timer which disables each component of a circuit while discharging an output voltage Vo using a control signal of a sleep timer in which a width of an OFF signal is larger than a width of an ON signal in a light load state and sequentially enables each component of the circuit while charging the output voltage in a predetermined order to minimize power consumption according to a loading level of a load.