Abstract: Provided is a hinge and a door mechanism that are mounted on a large-sized and heavy door that requires sealing property and difficult adjustment. The hinge includes: a fulcrum shaft; an adjustment shaft that is disposed adjacently to and parallel to the fulcrum shaft; a housing-side fixing portion that supports the fulcrum shaft; a door-side fixing portion that supports the adjustment shaft; and a link portion that allows the fulcrum shaft and the adjustment shaft to pass therethrough and connects the housing-side fixing portion and the door-side fixing portion to each other, wherein the body fixing portion includes an adjustment-use body fixing portion provided with a link adjustment portion that approximately fixes the link portion to an arbitrary angle with respect to the door-side fixing portion, and the body fixing portion includes at least two adjustment-use body fixing portions.