A connector includes a male terminal and a female terminal. At least one of the male terminal and the female terminal has an outermost surface layer formed of a metallic material as an alloy layer of Cu—Sn. The alloy layer of Cu—Sn has a concentration of Cu decreasing gradually toward a surface thereof. The metallic material for the connector includes the outermost surface layer formed of the alloy layer of Cu—Sn. The alloy layer of Cu—Sn has the concentration of Cu decreasing gradually toward the surface thereof.