A module 1 movable over the original surface 110 of the original reader 100 has a metal sheet frame 4 disposed in the vicinity of its gravitational center and having a substantially channel-like shape. A first and a second optical systems 2 and 3 and a drive source 6 assembled to be integral with a flat part 40 of the metal sheet frame 4. Thus, a reduced-size, improved quality and improved-accuracy original reader to be used for facsimile devices and image scanners is obtained.