The present invention is directed to a wafer holder and a related wafer conveyor system. The wafer holder holds a wafer and moves horizontally within a chamber. A contact area between the wafer and the wafer holder is reduced, and potential contaminants generated by ear between components of the wafer holder are trapped by an airtight cover. Since the wafer holder moves horizontally while being fixed to a guide rail, the wafer conveyor system reduces friction between the guide rail and the wafer holder.