Abstract: There is disclosed herein an attachment device for a camera unit adapted for viewing or shooting a scene from one side of a camera attachment plate, that is on the other side of the plate. The camera attachment unit includes the camera attachment plate provided with a through-hole, a camera lens body tube introduced into said through-hole, a positioning member provided to the forward or foremost part of the camera lens body tube, and a camera part to which the body tube is affixed. The camera part has a pair of pivot arms pivotally mounted on its surface facing the attachment plate. One of the pivot arms is pivotally mounted at its bottom or back end to the camera part, while the other pivot arm is slidably mounted at its bottom or back end along a guide groove on the surface of the camera part facing the camera attachment plate. The forward or foremost parts of these pivot arms are provided with cushioning members for cushioning against the camera attachment plate.