An imager apparatus is provided, including a housing that stores a lens device with an imaging lens exposed to the front surface facing a subject; a lens cover movable between a first position covering the imaging lens and a second position opening the same; and a cover moving mechanism linearly moving the lens cover between the first and second positions. The cover moving mechanism includes a plurality of brackets provided on the lens cover; a plurality of opening portions provided in the front surface of the housing, corresponding to the plurality of brackets, through which the tips of the brackets penetrate; an arm member fixed to those brackets on the inner side of the housing; a guide member guiding the arm member in the moving direction of the lens cover; and a slide joining mechanism joining the arm member to the guide member in a slidable manner.