An optical disk device has a casing, an insertion slot and a loading mechanism for loading a disk. A shutter is shiftable transversely to an elongate slot shape of the insertion slot, closes the insertion slot partially when in a closed position, and opens the insertion slot when in an open position. A coupling hole is disposed at an end of the shutter with respect to the elongate slot shape. A shift lever moves the coupling hole in a first direction along the elongate slot shape upon shifting of the loading mechanism for loading, and moves the coupling hole in a second direction upon shifting of the loading mechanism for unloading. A cam mechanism shifts the shutter to the closed position when the coupling hole is moved in the first direction, and shifts the shutter to the open position when the coupling hole is moved in the second direction.