A substrate-design assistance device (1) comprises: a design-data acquisition unit (11) for acquiring design data on a printed circuit board; a first determination unit (13) for determining whether the longitudinal direction of the substrate fibers of the printed circuit board and the longitudinal direction of an electronic component disposed on the printed circuit board are perpendicular to each other on the basis of the design data on the printed circuit board; a second determination unit (14) for determining, on the basis of the design data on the printed circuit board, whether wires are laterally drawn from pads to which the electronic component disposed on the printed circuit board is connected; and a notification unit (15) for providing a notification about error information on electronic components where it has been determined that the longitudinal directions are not perpendicular to the longitudinal direction of substrate fibers and wires are not laterally drawn from pads.