To appropriately manufacture a semiconductor device. A glass substrate is a glass substrate for manufacturing the semiconductor device. In a case in which one surface is directed downward in a vertical direction, and a first position, a second position, and a third position on the one surface on an outer side in a radial direction with respect to a center point of the glass substrate are supported by supporting members, a lowest point as a position where a height in the vertical direction is the lowest on other surface is positioned in a circular central region on an inner side in the radial direction with respect to the first position, the second position, and the third position when viewed from the vertical direction, a center of the central region is a center point of the glass substrate, and a diameter of the central region has a length of ⅓ of a diameter of the glass substrate.