At present there are many studies are carried out to develop micro parts. A micro drive unit assembled with several micro movable parts is needed to industrialize the functional micro parts such as micro pump, micro-chip, micro motor and micro gear etc. In this study, making micro metal gear with outer diameter 500um, a powder injection molding process was used. To make micro metal part, it is needed micro shape cavity & core in molds for filling of feedstocks there are several methods to make micro shape or pattern such as LIGA process, laser machining, micro etching and micro milling process etc. But these micro methods are expensive and needed some special facilities to fabricate. So in this study, conventional machining methods were tested to make micro gear cavity shape. The preliminary studies were conducted to evaluate the filling of cavity and machine that. Finally outer diameter 500um level micro gear was injection molded and debinded and sintered. Some incomplete filling was occurred in the end of filling at gear teeth using 17-4PH 3F feedstock. The final sintered micro metal gear showed about 434um of outer diameter.