Abstract: An auto power cut-off device for camera and a driving method which can automatically close an automatic lens cap and concurrently cut-off power supplied to an auxiliary circuit in case that a user does not use a camera during a predetermined time after supplying the power to the camera. The auto power cut-off device is constituted by a switch block including a power control for staring the operation of the automatic camera, an encoder switch which can be varied according to the state of the automatic camera, and an operation switch for controlling the operation of the camera. The power cut-off device also has a micro controller of outputting a signal to block the power supplied to the auxiliary circuits in case that the automatic camera is not used during a predetermined period after operation of the automatic camera beings; and a power control means for blocking the power supplied to the auxiliary circuits in case that the power cut-off signal is inputted from the micro controller.