PURPOSE: A gate valve is provided to minimize the weight which is applied to an elevating cylinder by including a cylinder supporting part which supports a sealing plate in order to be horizontally moved. CONSTITUTION: Housing is installed in the side wall of a chamber in order to face with a gate which is formed in the side wall of the chamber. The housing has a sealing hole which is opened in a gate direction and a bottom hole which is opened in a lower direction. A sealing plate(22) seals the gate by advancing and reversing in the gate direction. An elevating cylinder(60) combines with a module block in the lower part of the housing and elevates the module block. A bottom plate closes the bottom hole by being combined in the lower part of the housing and has a penetration hole in which the elevating cylinder passes through. A cylinder support(70) is combined to the lower part of the bottom plate.
