A copper alloy includes Si to facilitate deoxidation, and can be easily manufactured even when including elements such as Cr or Sn. The copper alloy has high conductivity and high workability without negatively affecting the tensile strength. The copper alloy contains 0.2 to 0.4 wt % of Cr, 0.05 to 0.15 wt % of Sn, 0.05 to 0.15 wt % of Zn, 0.01 to 0.30 wt % of Mg, 0.03 to 0.07 wt % of Si, with the remainder being Cu and inevitable impurities. A method for manufacturing the copper alloy includes obtaining a molten metal having the described composition; obtaining an ingot; heating the ingot at a temperature of 900-1000° C. to perform a hot rolling process; cold rolling; performing a first aging process at a temperature of 400-500° C. for 2 to 8 hours; cold rolling; and performing a second aging process at a temperature of 370-450° C. for 2 to 8 hours.