A copper-based alloy that has the soundness of alloy enhanced by restraining the concentrated occurrence of microporosities while suppressing the lead content and an ingot and a liquid-contacting part using the alloy are provided. The copper-based alloy has the soundness of alloy improved during the course of solidification of the copper-based alloy by crystallizing an intermetallic compound capable of solidifying at a temperature exceeding a solidus line in dendritic gaps of the alloy, suppressing migration of a solute, thereby allowing dispersion of microporosities, utilizing crystallization of the intermetallic compound as well for effecting dispersed crystallization of a low melting metal or a low melting intermetallic compound capable of solidifying at a temperature falling short of a liquidus line, and relying on the low melting metal or low melting intermetallic compound to enter the microporosities and suppress occurrence of microporosities.