The present invention relates to a switching mode power supply circuit for a plasma display panel comprising an input unit, a PFC (Power Factor Correction) unit, an output unit and a standby unit, wherein the standby unit includes a standby block for outputting a standby voltage by being connected to an AC filter stage of the input unit, a sequence block for sequentially applying power of the output unit and a control block which is connected between the standby block and the sequence block and inputs the standby voltage outputted from the standby block to the sequence block only in case that a PS_ON signal is applied.