Provided is a copper alloy sheet for a heat-dissipating component that has high strength, excellent bending workability and heat-dissipating properties. The copper alloy sheet contains 0.1-1.0 mass % of Ni, 0.01-0.3 mass % of Fe and 0.03-0.2 mass % of P, with the remainder comprising Cu and unavoidable impurities. In a direction parallel to the rolling direction, the tensile strength is 580 MPa or higher, the proof stress is 560 MPa or higher, and the elongation is 6% or higher. In a direction perpendicular to the rolling direction, the tensile strength is 600 MPa or higher, the proof stress is 580 MPa or higher, and the elongation is 3% or higher. When the electrical conductivity is 50% IACS or higher, the ratio between the bending radius R and the sheet thickness t (R/t) is set to be 0.5, and the sheet is bent at an angle of 90-degree with the direction of the bend line being a direction perpendicular to the rolling direction, the bending limit width is 70 mm or more, and when the sheet is subjected to close-contact bending with the direction of the bend line being a direction perpendicular to the rolling direction, the bending limit width is 20 mm or more.