A copper-based alloy includes one base phase selected from the group consisting of .alpha. phase, .alpha.+.beta. phase, and .alpha.+.beta.+.gamma. phase, a component having a lower melting point than the base phase, and a component for dispersing the base phase and the low melting component to uniformly disperse the low melting component and improve the copper-based alloy in machinability. A method for producing the copper alloy in the form of a bar or plate includes the steps of compounding raw materials in predetermined ratios thereby obtaining a mixture, fusing the mixture thereby obtaining a melt, continuously casting the melt into a cast billet, or rolling the cast billet thereby obtaining a shaped mass, heat-treating the shaped mass, drawing or rolling the heat-treated shaped mass thereby obtaining a plastic mass, and subjecting the plastic mass to a heat-treatment of air cooling or furnace cooling.