A method of manufacturing a semiconductor element, comprising: providing a substrate having a first surface and an opposite second surface, wherein the first surface is parallel to a plane that extends in a first direction and in a second direction intersecting the first direction; performing a first irradiation step comprising irradiating, in a thickness direction of the substrate, a laser beam from the first surface to an interior of the substrate along the first direction parallel to the first surface, so as to form a plurality of first modified portions (a) aligned along the first direction in the interior of the substrate, and a first crack (cr) extending from at least one of the plurality of first modified portions (a) toward at least the first surface; after performing the first irradiation step, performing a second irradiation step comprising irradiating, in the thickness direction of the substrate, the laser beam from the first surface to a position shifted from the first modified portions (a) in a second direction intersecting with the first direction and parallel to the first surface, so as to form a plurality of second modified portions (b) aligned along the first direction at a position adjacent to the plurality of first modified portions (a) in the second direction, and a second crack (cr) extending from at least one of the plurality of second modified portions (b) toward at least the first surface; after performing the second irradiation step, performing a third irradiation step comprising irradiating, in the thickness direction of the substrate, the laser beam from the first surface side along the first direction, so as to form a plurality of third modified portions (c) aligned along the first direction at a position that (i) is closer to the first surface than is the plurality of first modified portions (a) and (ii) overlaps the plurality of first modified portions (a) in a thickness direction of the substrate; and after performing the third irradiation, cutting the substrate, which comprises pressing the substrate from a second surface side with a pressing member, wherein no modified portion is formed at a position that is (i) adjacent to the third modified portions (c) in the second direction and (ii) overlaps the second modified portions (b) in the thickness direction of the substrate, wherein, in the step of cutting the substrate, the substrate is pressed with the second crack (cr) not reaching the first surface and a third crack (cr) extending from at least one of the plurality of third modified portions (c) reaching the first surface. providing a substrate having a first surface and an opposite second surface, wherein the first surface is parallel to a plane that extends in a first direction and in a second direction intersecting the first direction; performing a first irradiation step comprising irradiating, in a thickness direction of the substrate, a laser beam from the first surface to an interior of the substrate along the first direction parallel to the first surface, so as to form a plurality of first modified portions (a) aligned along the first direction in the interior of the substrate, and a first crack (cr) extending from at least one of the plurality of first modified portions (a) toward at least the first surface; after performing the first irradiation step, performing a second irradiation step comprising irradiating, in the thickness direction of the substrate, the laser beam from the first surface to a position shifted from the first modified portions (a) in a second direction intersecting with the first direction and parallel to the first surface, so as to form a plurality of second modified portions (b) aligned along the first direction at a position adjacent to the plurality of first modified portions (a) in the second direction, and a second crack (cr) extending from at least one of the plurality of second modified portions (b) toward at least the first surface; after performing the second irradiation step, performing a third irradiation step comprising irradiating, in the thickness direction of the substrate, the laser beam from the first surface side along the first direction, so as to form a plurality of third modified portions (c) aligned along the first direction at a position that (i) is closer to the first surface than is the plurality of first modified portions (a) and (ii) overlaps the plurality of first modified portions (a) in a thickness direction of the substrate; and after performing the third irradiation, cutting the substrate, which comprises pressing the substrate from a second surface side with a pressing member, wherein no modified portion is formed at a position that is (i) adjacent to the third modified portions (c) in the second direction and (ii) overlaps the second modified portions (b) in the thickness direction of the substrate, wherein, in the step of cutting the substrate, the substrate is pressed with the second crack (cr) not reaching the first surface and a third crack (cr) extending from at least one of the plurality of third modified portions (c) reaching the first surface.