A Cu—Ni—Co—Si based copper alloy sheet material has second phase particles existing in a matrix, with a number density of ultrafine second phase particles is 1.0×109 number/mm2 or more. A number density of fine second phase particles is not more than 5.0×107 number/mm2. A number density of coarse second phase particles is 1.0×105 number/mm2 or more and not more than 1.0×106 number/mm2. The material has crystal orientation satisfying the following equation (1): I{200}/I0{200}≧3.0  (1) wherein I{200} represents an integrated intensity of an X-ray diffraction peak of the {200} crystal plane on the sheet material sheet surface; and I0{200} represents an integrated intensity of an X-ray diffraction peak of the {200} crystal plane in a pure copper standard powder sample.