To solve such problems in the casting of a copper alloy containing high concentration of Sn to develop a casting crack because the fluidity of this molten metal is low and the γ-phase is precipitated at the cooling time if the alloy is a brass and to add lead for improving the fluidity.

A brass cast member is made to contain 33.5-43 wt.% Zn and 0.5-8.0 wt.% Sn on the apparent contents and to have 0.5-4 mm thickness and ≤10% residual ratio of the γ-phase after casting. When a dezincing corrosion test according with Technical Standards in Japan Brass Makers Association (JBMA) T-303 is applied, in the case of being the parallel with the working direction, to the maximum dezincing penetrating depth direction, the maximum dezincing depth is made to ≤100 μm or in the case of being the right angle to the working direction, to the maximum dezincing penetrating depth direction, the maximum dezincing depth is made to ≤70 μm.