A metal structure (101) having a substantially U-letter shape is provided in a chassis. Tripod screw attaching portions (102a) are provided to the upper and lower portions of the metal structure. A casing is arranged to cover the front surface of the front portion and the lower surface of the rear portion of the metal structure (101). A metal chassis panel (105, 106) is attached to cover at least the left and right surfaces of the metal structure. The casing portion of the front surface of the metal structure is substantially curved to enable tally lamp light to be recognized at the casing portion of the front surface.