A cooling structure comprising: a press forming member having a groove part and a bank part provided around the groove part; a flow path upper lid which is a flat sheet overlapped at a position covering the groove part of the press forming member and forms a flat cooling surface; and a joint portion which joins opposing surfaces of the flow path upper lid and the bank part to form a flow path through which a cooling liquid is capable of flowing, wherein the press forming member and the flow path upper lid are plated steel sheets having a base steel sheet, the joint portion is made of a joining metal which brazes the base steel sheets of the press forming member and the flow path upper lid to each other, the flow path includes a parallel flow path portion in which a plurality of partial flow paths extending along a first direction are arranged in a second direction orthogonal to the first direction, and characterized in that the plated steel sheets have an Al-based plating having a film thickness of 10.0 μm or more, or a Zn-based plating having a film thickness of 5.0 μm or more, in which a sheet thickness of the plated steel sheets is 0.3 mm to 1.2 mm, and in a cross section of the parallel flow path portions perpendicular to the first direction, when a width of a region, in which a distance between the bank part and the flow path upper lid is less than 0.5 mm, and which is located between adjacent partial flow paths, is defined as a partial flow path interval, and a width of the joining metal located between the adjacent partial flow paths is defined as a joining width, the partial flow path interval is 20 mm or less and the joining width is 3 mm or more in a part or all of the parallel flow path portions. a press forming member having a groove part and a bank part provided around the groove part; a flow path upper lid which is a flat sheet overlapped at a position covering the groove part of the press forming member and forms a flat cooling surface; and a joint portion which joins opposing surfaces of the flow path upper lid and the bank part to form a flow path through which a cooling liquid is capable of flowing, wherein the press forming member and the flow path upper lid are plated steel sheets having a base steel sheet, the joint portion is made of a joining metal which brazes the base steel sheets of the press forming member and the flow path upper lid to each other, the flow path includes a parallel flow path portion in which a plurality of partial flow paths extending along a first direction are arranged in a second direction orthogonal to the first direction, and characterized in that the plated steel sheets have an Al-based plating having a film thickness of 10.0 μm or more, or a Zn-based plating having a film thickness of 5.0 μm or more, in which a sheet thickness of the plated steel sheets is 0.3 mm to 1.2 mm, and in a cross section of the parallel flow path portions perpendicular to the first direction, when a width of a region, in which a distance between the bank part and the flow path upper lid is less than 0.5 mm, and which is located between adjacent partial flow paths, is defined as a partial flow path interval, and a width of the joining metal located between the adjacent partial flow paths is defined as a joining width, the partial flow path interval is 20 mm or less and the joining width is 3 mm or more in a part or all of the parallel flow path portions.