A　new　optimized　structure　of　micro　electromagnetic　relay　was　introduced,　and　its　working　principle　was　presented.　By　analysis　of　the　driving　force　and　the　displacement　of　the　armature,　a　three-dimensional　structure　was　designed　to　increase　the　efficiency　of　magnetic　circuit.　A　prototype　micro　electromagnetic　relay　with　dimension　of　5　mm　×　5　mm　×　1　mm　was　fabricated　based　on　the　microelectromechanical　system　(MEMS)　fabrication　process.　The　micro　electromagnetic　relay　consists　of　magnetic　circuit,　excitation　planar　coil,　fixed　contact　pad　and　permalloy　cantilever　(armature).　Experimental　result　shows　that　when　the　micro　electromagnetic　relay　in　the　resistance　of　the　excitation　coil　of　20　Ω　works　at　5　V,　its　contact　resistance　is　14.5　Ω　and　response　time　is　about　1　ms　under　the　electromagnetic　actuation.