Disclosed is a processing apparatus to restrain load of a common usage system shared by a plurality of liquid processing modules. A processing module group includes k sets of share groups comprising a plurality of processing modules to perform an identical processing for each substrate (where, k≧2), each set of share groups includes n processing modules (where, n≧2), and each processing module includes the common usage system shared by n processing modules in each set and having a maximum capacity capable of processing m processing modules (where m≦n). A carrying mechanism repeatedly loads a substrate one by one to the processing module of each set in sequence. At this time, (1) after the completion of the processing in one processing module that uses the common usage system, the substrate is loaded into another processing module in the same set, or (2) without waiting for the completion of the processing in one processing module, the substrate is loaded into another processing module and then the processing is started in another processing module after the completion of the processing in one processing module.