In　micro　electrochemical　machining(ECM)processes,stray　corrosion　causes　undesired　metal　dissolu-tion　and　the　deterioration　of　shape　accuracy.Adopting　a　sidewall-insulated　electrode　is　an　effective　approach　to　sup-pressing　stray　corrosion.Most　sidewall-insulated　electrodes　are　made　of　metal　substrate　and　non-metallic　thin　films.Nevertheless,the　thin-film　insulating　materials　attached　to　a　metal　substrate　are　susceptible　to　damage　in　an　electro-lytic　environment.This　study　presents　a　novel　concept　of　the　conductive-material-filled　electrode　for　better　sidewall-insulation　performance.The　micro-scale　quartz　tube　serves　as　the　insulating　substrate.Commercially　available　conduc-tive　fillers　including　metal　wire,molten　metals,and　silver　powder　are　filled　inside　the　working　cathode　of　the　quartz　tube.Consequently,the　metal-wire-filled　electrode,molten-metal-filled　electrode,and　nano-powder-filled　electrode　are　designed　and　fabricated.From　the　verification　results　of　electrode　toughness,material　removal　rate,and　surface　topography,the　metal-wire-filled　electrode　and　molten-metal-filled　electrode　exhibit　the　same　performance　as　a　traditional　metal-based　electrode　and　much　better　durabil-ity.By　contrast,the　nano-powder-filled　electrode　is　unable　to　withstand　long-term　ECM　processes　because　of　the　loss　of　cured　powder　particles.In　ECM　experiments,microstruc-tures　with　steep　sidewalls(taper　angle＜9.7°)were　machined　using　the　metal-wire-filled　electrode　and　molten-metal-filled　electrode,which　could　replace　the　traditional　electrode,achieving　a　longer　service　life　and　superior　sidewall-insu-lation　performance.