Disclosed is a remote monitoring terminal device including: connection terminals (T, . . . ); a data storage control section for storing, in a first data storage section at predetermined intervals, only a predetermined number of latest data sets fed via the connection terminals (T, . . . ); a sampling data storage control section for storing in a second data storage section sampling data obtained by sampling the data stored in the first data storage section at sampling intervals (TC); and a communications section, wherein the sampling data storage control section transmits the sampling data stored in the second data storage section to the remote monitoring device via the communications section in response to a request from the remote monitoring device or in response to an end of a work.