A processing device comprising: a requesting section (31, 34) adapted to issue a request to a server to transmit processing data; a receiving section (31, 32, 34) adapted to receive the processing data transmitted from the server in response to the request to transmit; a processing section (31, 33, 35) adapted to sequentially make the processing data received by the receiving section a processing object, and conduct processing based on the processing data that is made a processing object; a measuring section adapted to measure a data amount (n) of the processing data that has been made a processing object by the processing section among the received processing data; a first storing section; and a second storing section, wherein in a case where a session between the server and the processing device is disconnected before all the processing data is made a processing object and thereafter the session is reconnected, after the session is reconnected, the processing section is adapted to conduct processing with respect to the first portion (d3; d3, d4) that is not yet made a processing object among the processing data based on the data amount measured by the measuring section when the server is disconnected, and not to conduct processing with respect to the second portion (d1, d2; d1, d2, d3) that is already made a processing object among the processing data, the processing data is print data, and the processing section is adapted to conduct printing based on the acquired print data, and the receiving section is adapted to cause the first storing section to store the received processing data, the processing section is adapted to transfer the processing data before processing to the second storing section as the processing object and conduct processing based on the transferred data, and characterized in that the measuring section is adapted to measure the data amount of the processing data transferred from the first storing section to the second storing section, the requesting section is adapted to issue the request to the server to transmit the processing data via the Internet, and the requesting section is adapted to issue the request to transmit a portion of the processing data that is not yet made a processing object through range specification by using a range header of HTTP. a requesting section (31, 34) adapted to issue a request to a server to transmit processing data; a receiving section (31, 32, 34) adapted to receive the processing data transmitted from the server in response to the request to transmit; a processing section (31, 33, 35) adapted to sequentially make the processing data received by the receiving section a processing object, and conduct processing based on the processing data that is made a processing object; a measuring section adapted to measure a data amount (n) of the processing data that has been made a processing object by the processing section among the received processing data; a first storing section; and a second storing section, wherein in a case where a session between the server and the processing device is disconnected before all the processing data is made a processing object and thereafter the session is reconnected, after the session is reconnected, the processing section is adapted to conduct processing with respect to the first portion (d3; d3, d4) that is not yet made a processing object among the processing data based on the data amount measured by the measuring section when the server is disconnected, and not to conduct processing with respect to the second portion (d1, d2; d1, d2, d3) that is already made a processing object among the processing data, the processing data is print data, and the processing section is adapted to conduct printing based on the acquired print data, and the receiving section is adapted to cause the first storing section to store the received processing data, the processing section is adapted to transfer the processing data before processing to the second storing section as the processing object and conduct processing based on the transferred data, and characterized in that the measuring section is adapted to measure the data amount of the processing data transferred from the first storing section to the second storing section, the requesting section is adapted to issue the request to the server to transmit the processing data via the Internet, and the requesting section is adapted to issue the request to transmit a portion of the processing data that is not yet made a processing object through range specification by using a range header of HTTP.