A member supporting method for supporting a member using support pins includes: an abutting step (S1) of abutting an end of each of a plurality of support pins facing a surface to be supported of the member against the member by moving the plurality of support pins in a supporting direction which is a direction in which the support pins support the member; and a fixing step (S2) of fixing the plurality of support pins in position with the end of each of the plurality of support pins abutted against the member and located along irregularities on the surface to be supported in the abutting step (S1), and thereby restricting movement of the plurality of support pins in both directions parallel to the supporting direction.