Abstract: There is disclosed a door operation mechanism which can open/close a door to either right or left side. When a handle portion 116 is manually pivoted and displaced, it rotates cams 98 and 98a and, thus, a thrust-up rod 94 is pushed up and a push-down rod 94a is pushed down. The thrust-up rod 94 pushes and displaces a swing plate 66 in a hinge mechanism 16a. The push-down rod 94a pushes and displaces a swing place 66 in a hinge mechanism 16b. Then, the swing plates 66 in the hinge mechanisms 16a and 16b fail to bind hinge pins 22 and 26, respectively, and the right side of a door 14 is released. By pulling the right side of the door 14, the door 14 can be opened on the axis of hinge mechanisms 16c and 16d which are provided on the left side of the door. On the other hand, when a left unlocking mechanism 20b is operated, the door 14 can be opened on the axis of the hinge mechanisms 16a and 16b on the right side of the door. Therefore, the door 14 can be opened to either right or left side.