Disclosed is a copper alloy. The copper alloy consists essentially ofCu:jj$ Jb 88 mass%, Si: 2 to 5 mass%, Zr : 0.0005 to 0.04 mass%, P : 0.01 to 0.25 mass%, and Zn : balance has relation of, in terms of a content of an element a, [a] mass%, fO = [Cu] - 3.5[Si] - 3fP] = 61 to 71, fl = [P]/[Zr] - 0.7 to 200, £2 = [Si]/[Zr] - 75 to 5000, and f3 = [Si/[P] = 12 to 240 has a metal structure that contains a phase and, K phase and/or y phase, and has relation of, in terms of a content of a phase b, [b]%, in an area rate, f4 = [a] + [y] + [K] > 85 and f5 - [y] + [K] + 0.3[n] - [P] = 5 to 95 and has an average grain diameter of 200 ^im or less in a macrostructure when melted and solidified.
