A laser welding method for joining a first member (521, 554, 558) in the shape of a plate and made of a metal material to a second member (522, 555, 559) configured as a pipe member made of a metal material by laser welding, the laser welding method comprising: an arranging step of bringing the second member (522, 555, 559) into contact with or close to one main surface (554b, 558b, 565b) of the first member (521, 554, 558); and a laser beam irradiation step of irradiating a laser beam to the other main surface (521a, 554a, 558a) of the first member (521, 554, 558), the other main surface (521a, 554a, 558a) being a main surface opposite to the one main surface (521b, 554b, 558b) of the first member (521, 554, 558) which the second member (522, 555, 559) is brought into contact with or brought close to, wherein in the laser beam irradiation step, the first member (521, 554, 558) and the second member (522, 555, 559) are melted to form a plurality of weld portions having substantially circular or oval shapes in a plan view at a distance from each other and to form a linear weld portion having a linear shape in the plan view to connect the weld portions adjacent to each other, and to form a fillet on a joined portion between the first member (521, 554, 558a) and the second member (522, 555, 559), wherein the forming of the plurality of weld portions having a substantially circular or oval shape and the forming of the linear weld portion having a linear shape to connect the weld portions adjacent to each other are performed one after another, wherein an area in which a gap between an outer peripheral surface of the second member and the one main surface of the first member which the second member is brought into contact with or brought close to is equal to or smaller than 1/2 of a thickness of the first member is projected over the other main surface of the first member and the projected area is a given area that is irradiated with the laser beam, wherein the projected area is defined by intersections (P1, P2) of a first virtual line parallel to the one main surface of the first member which the second member is brought into contact with or brought close to and the outer peripheral surface of the second member, which are projected to the other main surface of the first member by second virtual lines (L1, L2) being perpendicular to the other main surface, wherein the first virtual line has a distance to the one main surface equal to or smaller than 1/2 of the thickness of the first member. an arranging step of bringing the second member (522, 555, 559) into contact with or close to one main surface (554b, 558b, 565b) of the first member (521, 554, 558); and a laser beam irradiation step of irradiating a laser beam to the other main surface (521a, 554a, 558a) of the first member (521, 554, 558), the other main surface (521a, 554a, 558a) being a main surface opposite to the one main surface (521b, 554b, 558b) of the first member (521, 554, 558) which the second member (522, 555, 559) is brought into contact with or brought close to, wherein in the laser beam irradiation step, the first member (521, 554, 558) and the second member (522, 555, 559) are melted to form a plurality of weld portions having substantially circular or oval shapes in a plan view at a distance from each other and to form a linear weld portion having a linear shape in the plan view to connect the weld portions adjacent to each other, and to form a fillet on a joined portion between the first member (521, 554, 558a) and the second member (522, 555, 559), wherein the forming of the plurality of weld portions having a substantially circular or oval shape and the forming of the linear weld portion having a linear shape to connect the weld portions adjacent to each other are performed one after another, wherein an area in which a gap between an outer peripheral surface of the second member and the one main surface of the first member which the second member is brought into contact with or brought close to is equal to or smaller than 1/2 of a thickness of the first member is projected over the other main surface of the first member and the projected area is a given area that is irradiated with the laser beam, wherein the projected area is defined by intersections (P1, P2) of a first virtual line parallel to the one main surface of the first member which the second member is brought into contact with or brought close to and the outer peripheral surface of the second member, which are projected to the other main surface of the first member by second virtual lines (L1, L2) being perpendicular to the other main surface, wherein the first virtual line has a distance to the one main surface equal to or smaller than 1/2 of the thickness of the first member.