A joint body comprising: a first metal member; a second metal member placed on the first metal member; and a joint portion including a welded portion where the first metal member and the second metal member are joined together, the welded portion having a line shape, wherein the joint portion includes: a first longitudinal portion extending in a first direction, the first longitudinal portion having first intersecting portions arranged in the first direction, the welded portion intersecting itself at the first intersecting portions; a second longitudinal portion located apart from the first longitudinal portion in a second direction intersecting the first direction and extending in the first direction, the second longitudinal portion having second intersecting portions arranged in the first direction, the welded portion intersecting itself at the second intersecting portions; and a plurality of connecting portions arranged in the first direction, each extending in the second direction and connecting the first longitudinal portion and the second longitudinal portion, characterized in that each of the first longitudinal portion and second longitudinal portion includes a straight-line-like portion extending in the first direction, wherein an irradiation pattern has an isosceles trapezoidal shape whose upper base and lower base extend in a welding direction, wherein the first direction coincides with the welding direction and a direction opposite to the welding direction, wherein the first longitudinal portion and the second longitudinal portion linearly extend in the welding direction, and wherein the connecting portions linearly extend to connect the first longitudinal portion and the second longitudinal portion. a first metal member; a second metal member placed on the first metal member; and a joint portion including a welded portion where the first metal member and the second metal member are joined together, the welded portion having a line shape, wherein the joint portion includes: a first longitudinal portion extending in a first direction, the first longitudinal portion having first intersecting portions arranged in the first direction, the welded portion intersecting itself at the first intersecting portions; a second longitudinal portion located apart from the first longitudinal portion in a second direction intersecting the first direction and extending in the first direction, the second longitudinal portion having second intersecting portions arranged in the first direction, the welded portion intersecting itself at the second intersecting portions; and a plurality of connecting portions arranged in the first direction, each extending in the second direction and connecting the first longitudinal portion and the second longitudinal portion, characterized in that each of the first longitudinal portion and second longitudinal portion includes a straight-line-like portion extending in the first direction, wherein an irradiation pattern has an isosceles trapezoidal shape whose upper base and lower base extend in a welding direction, wherein the first direction coincides with the welding direction and a direction opposite to the welding direction, wherein the first longitudinal portion and the second longitudinal portion linearly extend in the welding direction, and wherein the connecting portions linearly extend to connect the first longitudinal portion and the second longitudinal portion. a first longitudinal portion extending in a first direction, the first longitudinal portion having first intersecting portions arranged in the first direction, the welded portion intersecting itself at the first intersecting portions; a second longitudinal portion located apart from the first longitudinal portion in a second direction intersecting the first direction and extending in the first direction, the second longitudinal portion having second intersecting portions arranged in the first direction, the welded portion intersecting itself at the second intersecting portions; and a plurality of connecting portions arranged in the first direction, each extending in the second direction and connecting the first longitudinal portion and the second longitudinal portion, characterized in that each of the first longitudinal portion and second longitudinal portion includes a straight-line-like portion extending in the first direction, wherein an irradiation pattern has an isosceles trapezoidal shape whose upper base and lower base extend in a welding direction, wherein the first direction coincides with the welding direction and a direction opposite to the welding direction, wherein the first longitudinal portion and the second longitudinal portion linearly extend in the welding direction, and wherein the connecting portions linearly extend to connect the first longitudinal portion and the second longitudinal portion.