The possibility of obtaining a bicontinuous microstructure through partial melting of solid solutions is explored in this study. A Cu-In solid solution was heated into the solid/melt two phase region of the alloy phase diagram and then quenched in water. A granular structure consisting of (1) the solidified In-enriched melt and (2) the Cu solid solution phase was obtained. The former phase was removed by electrochemical dealloying, and a continuous load-bearing backbone was left. This proves that a bicontinuous microstructure can form during partial melting and remains preserved after quenching to ambient. This special structure is the combined result of a discontinuous composition-equilibrating reaction by liquid film migration and the associated coarsening. This research provides new a method for the preparation of monolithic interpenetrating-phase composites or porous metals, as extended melting intervals are ubiquitous in binary alloys.