A lid mechanism includes a divided lid for closing an opening extending in a longitudinal direction in a closed position, and a lid operating mechanism disposed below the opening closed by the divided lid. The divided lid has at least a front lid for closing a front part of the opening in the closed position and a rear lid for closing a rear part of the opening in the closed position. With the lid operating mechanism, the front lid in the closed position slides from a front part side to a rear part side and enters below the rear lid in the closed position in an overlapped state. Then, the front lid moves downwardly together with the rear lid in the overlapped state while a front end of the front lid faces upwardly.