To provide a door device capable of easily opening and closing a passage, without having as motive power source, while restraining an installation space.

The upper-lower ends of a door 1 for opening and closing the passage, is provided with flat, annular and elliptic guide rails 4 and 8. These guide rails 4 and 8 are respectively sandwiched by a pair of roller-shaped guide members 6, 7, 9 and 10. The door 1 is composed of upper-lower support mechanisms 3 and 5 constituted in this way so as to be freely openable-closable/rockable and freely longitudinally movable. An expansion spring 13 is installed between a spring support piece 14 in the substantial center in the door longitudinal direction of the door 1 and a fastener 15 arranged in an upper frame 2, and is constituted to be energized in its blocking-up position direction to the door 1. The expansion spring 13 is expanded and deformed in response to the opening movement of the door 1, and restoring force for energizing the door 1 in the blocking-up position direction, is stored in the expansion spring 13, and the door 1 can be closed and moved by this restoring force.