Provided are an auxiliary power supply test method and an electronic apparatus to which the same is applied. The auxiliary power supply test method includes: applying a charging disable signal, which interrupts a charging operation by an auxiliary power supply unit for a predetermined period of time, to the auxiliary power supply unit; monitoring a charging voltage of the auxiliary power supply unit in a time interval in which the charging disable signal is applied to the auxiliary power supply unit; determining whether the auxiliary power supply unit is defective, based on whether the monitored charging voltage is less than a predetermined threshold voltage, wherein the auxiliary power supply unit supplies auxiliary power, obtained based on the charging voltage, to a system power supply line in a case of a sudden power-off.