An image forming apparatus includes a body cover pivotally mounted on a body of the image forming apparatus and a switch mechanism for detecting an opening/closing status of the body cover. The switch mechanism includes a switch disposed in the body and a cam disposed beside the switch for activating the switch when rotated in a prescribed direction. The switch mechanism further includes a lever with one end supported by the body cover while another end contacts and rotates the cam by a prescribed constant amount of a rotational angle when the body cover is closed.