A network system uses a management routing instance to route management information between elements involved in management of the system. a plasma processing apparatus 2 that subjects semiconductor wafers W to plasma processing in a cleaned atmosphere. The lower half fan blade includes a plurality of wood sheets, and the upper half fan blade is laminated on the lower half fan blade in such a manner that abutting sides of the upper half fan blade are staggered with respect to abutting sides of the lower half fan blade, so that the strength of the ceiling fan blade can be improved.