Gate valve

A gate valve according to the present invention comprises: a valve case having a first opening and a second opening; a valve body positioned in the hollow part in the valve case; a rotating shaft supporting the valve body; a rotation drive unit capable of rotationally driving the valve body; a neutral valve part connecting the valve body to the rotating shaft; a movable valve frame part arranged on the valve body; a valve frame biasing part connecting the neutral valve part and the movable valve frame part; a movable valve plate part arranged on the valve body; a valve plate biasing part connecting the movable valve frame part and the movable valve plate part; a valve case biasing part capable of moving the movable valve frame part towards a valve closing position in contact with the periphery of the first opening; and a drive unit for driving the valve case biasing part. The valve frame biasing part comprises a valve frame guide pin fixed on one of the neutral valve part and the movable valve frame part; a t