In　this　paper,　we　proposed　two　types　of　spiral　microrobot　that　can　move　in　human　organs　such　like　intestines,　even　blood　vessels　as　an　assumption　has　a　great　potential　application　for　microsurgery.　We　begin　with　a　mechanical　study　of　the　fish-like　microrobot　made　by　magnetic　actuator.　And　then,　based　on　the　previous　researches,　the　structures　of　the　developed　microrobot　have　been　designed.　By　applying　the　alternate　magnetic　field,　the　developed　microrobots　can　be　manipulated　with　rotation　movement　in　a　pipe.　And　also,　the　motion　mechanism,　and　characteristic　evaluation　of　the　microrobot　have　been　discussed,　and　the　speed　of　rotation　movement　can　be　controlled　via　frequency　of　the　input　current.　The　characteristic　of　the　microrobot　has　been　evaluated　in　this　research.　We　aim　that　the　microrobot　has　a　rapid　response,　and　it　can　clear　out　dirt　which　is　adhering　to　the　inner　wall　of　pipe.　This　microrobot　will　play　an　important　role　in　both　industrial　and　medical　applications　such　as　microsurgery.　©　2008　IEEE.