A Cu-Zn alloy microchannel lining layer was fabricated by a powder-metallurgical process using Cu powder and Zn wire. The effects of the dealloying treatment on the composition and structure of the lining layer were investigated. The lining layer became more porous and dezinced as the dealloying time increased. In the case of long-time dealloying, Zn-based corrosion products precipitated. These results indicated the possibility of the control of the structure and composition of the inner wall of the microchannel.