A tonneau cover device (60) moves a tonneau cover (42), which is coupled to a hatchback door of a vehicle (2), between an extension position and a storage position. The tonneau cover device (60) includes a detection unit (22) and a controller (22). The detection unit (22) detects whether a pre-operation (39) for opening the hatchback door has been performed. The controller (22) permits movement of the tonneau cover (42) to the extension position when a courtesy switch (38), which is arranged in the vehicle (2), detects that the hatchback door is closed and the detection unit (22) does not detect that the pre-operation (39) has been performed. The controller (22) restricts movement of the tonneau cover (42) to the extension position when the courtesy switch (38) detects that the hatchback door is closed and the detection unit (22) detects that the pre-operation (39) has been performed.
