Provided is an apparatus for manufacturing a double-sided mounting substrate, the apparatus including: a backup table provided under the printed circuit board at the mounting position which supports the lower surface of the printed circuit board; and a servo motor which elevates and lowers the backup table, wherein the servo motor elevates the backup table to mount the new electronic components and lowers the backup table to carry-in and to carry-away the printed circuit board based on a lower limit position of the backup table, and wherein the lower limit position of the backup table is a position separated downwardly from a reference surface at the mounting position by a distance obtained by adding a preset clearance to a sum of a maximum height of the mounted electronic components mounted on the lower surface of the printed circuit board and a thickness of the printed circuit board.