An electronic apparatus comprises a switch, a processing unit, a functional unit and a power management unit. The function unit has a timer. The power management unit is coupled to the processing unit and the function unit. The processing unit and the function unit receive a switch signal generated by the switch. The processing unit generates a power-down signal after detecting a change in the logic level of the switch signal received for a first predetermined time. The timer starts counting upon detecting a change in the logic level of the switch signal, and executes a power-down procedure after the timer has counted to a second predetermined time. The second time is less than the first predetermined time. The function unit completes the power-down procedure before the power management unit receives the power-down signal and stops powering the processing unit and the function unit.