A copper alloy sputtering target most suitable for formation of an interconnection material of a semiconductor device, particularly for formation of a seed layer, characterized in that the target contains 0.4 to 5 wt % of Sn, and the structure of the target does not substantially contain any precipitates, and the resistivity of the target material is 2.2 μΩcm or more. This target enables formation of an interconnection material of a semiconductor device, particularly a uniform seed layer stable during copper electroplating and is excellent in sputtering deposition characteristics. A method for manufacturing such a target is also disclosed.