Stage supporting apparatus, alignment apparatus, film forming apparatus, mask mounting method, film forming method, and electronic device manufacturing method

The invention provides a stage supporting apparatus, an alignment apparatus, a film forming apparatus, a mask mounting method, a film forming method, and a method for manufacturing an electronic device. In the stage supporting apparatus for mounting a substrate stage holding a substrate on a mask, the control accuracy of the relative position of the substrate stage and the mask is improved. The stage support member includes: a plurality of first support portions arranged in parallel in a first direction along a film formation surface of the substrate and supporting a peripheral edge portion of a first side of the substrate stage in the first direction; and a plurality of second support parts which are arranged side by side in the first direction and support the peripheral edge part of the second side of the substrate stage along the first direction. The height of a part of the support surfaces of the plurality of first support parts is different from the height of another part of the support surfaces of the p