A processing device has a requesting section that issues a request to transmit processing data to a server; a receiving section that receives the processing data transmitted from the server in response to the request; a processing section that sequentially makes the received processing data a processing object, and conducts processing based on the processing data that is made a processing object; and a measuring section that measures a data amount of the processing data that has been made a processing object among the received processing data. In a case where a session between the server is disconnected before all the processing data is made a processing object and thereafter the session is reconnected, the processing section conducts processing with respect to a portion that is not yet made a processing object based on the data amount have measured when the server is disconnected.