A copper alloy powder for an electrically conductive paste is provided, which is characterized in that the copper alloy powder comprises 80 to 99.9 mass % of Cu and 0.1 to 20 mass % of one or two elements selected from the group consisting of Ta and W and has an average particle size of 0.1 to 1 .mu.m. This copper alloy powder has a higher starting temperature for sintering, higher oxidation resistance and better heat resistance than a copper powder.