A housing included in an optical disc device 1 includes a top case 2 and a bottom case 3. The top case 2 includes a ceiling plate 2a and side plates 2b. The bottom case 3 includes a bottom plate 3a and side plates 3b. The top case 2 and the bottom case 3 are assembled and fixed to each other so that the side plates 2b of the top case are located on the outer sides of the side plates 3b of the bottom case. The top case is formed with a groove 2d and flat portions 2e on an inner-side end portion of the ceiling plate 2a of the top case, the groove 2d and flat portions 2e extending along bent portions 2c of the side plates 2b of the top case. The flat portions shield the groove 2d.