A stage apparatus, which holds a plate member, comprises: a stage; a first positioning member and a second positioning member which are placed on the stage, and are configured to contact a lower surface and an upper surface of the plate member respectively to position the plate member in a direction perpendicular to a plane of the plate member; an elastic, first enclosing member configured to form a first enclosed space around the first positioning member; an elastic, second enclosing member configured to form a second enclosed space around the second positioning member; and a first suction mechanism and a second suction mechanism configured to respectively suck air from the first enclosed space and air from the second enclosed space so as to chuck the plate member to the first enclosed space and the second enclosed space by vacuum absorption.