To provide a valve device in which different driving mechanisms, that is, a rotating mechanism and a lifting mechanism are controlled by one driving source, thereby realizing compactness and high reliability of the driving mechanisms.
A valve device includes: a valve element unit 52 closing or opening a first opening 46 of a casing 44; a valve element driving unit 11 rotating the valve element unit 52 to move the valve element unit 52 to a position facing the first opening 46, and moving the valve element unit 52 in a radial direction to make the valve element unit 52 seated on the first opening 46; a first sealing member 58 provided on the valve element unit 52; and stoppers 39A, 39B, 35 restricting the rotation of the valve element unit 52, wherein the valve element driving unit 11 includes: a support 13 rotatably supporting the valve element unit 52; a shaft part 17 which has an eccentric shaft portion 17B connected to the valve element unit 52 and having a center located at a position a predetermined distance apart from a center of the rotation; and a driving source 66 rotating the shaft part 17.