The present investigation attempts to focus on the influence of EDM energy input on the structure and composition of the debris that forms during machining. An indigenously prepared ZrB2-Cu composite and mild steel plate were used as tool and workpiece (WP) material for the present study. The machining was carried out in a kerosene medium. The composition analysis of different debris particles was investigated by SEM/EDS. At low EDM energy input the SEM micrographs of WP debris showed formation of smaller size particles with few satellites. The SEM micrographs of high EDM energy input showed formation of hollow spheres, with dents, larger population of satellites, surface cracks and burnt core structures.