Abstract: A door panel retaining device includes a control knob for attaching to a door panel, one or more magnetically attractive members attached to the control knob, and another magnetically attractive member for attaching to the wall member and for acting with the magnetically attractive member of the control knob, and thus for attracting the control knob and the door panel to the wall member at an opening position. The door panel retaining device may be attached to the control knob of the door panel that is elevated and spaced away from the ground, to prevent the door panel retaining device from being wetted and rusted and damaged after use.