A remote monitoring terminal device for a mobile work vehicle or vessel, said remote monitoring terminal device being mounted to a mobile work vehicle or vessel for communication with a remote monitoring device to enable the mobile work vehicle or vessel to be remotely monitored by the remote monitoring device, said remote monitoring terminal device comprising: connection terminals for feeding data on an operation state of the mobile work vehicle or vessel; a data storage control section for temporarily storing, in a data storage section at predetermined intervals, only a predetermined number of latest data sets in the data fed via the connection terminals; and a communications section for communication with the remote monitoring device, wherein in response to an occurrence of a predetermined event in the mobile work vehicle or vessel, the data storage control section stores in the data storage section the predetermined number of data sets including a data set obtained upon the occurrence of the predetermined event and transmits the predetermined number of data sets stored in the data storage section, together with information indicating the predetermined event, to the remote monitoring device via the communications section, characterized in that the data storage control section transmits any single one of the predetermined number of data sets stored in the data storage section, as well as the information indicating the predetermined event, to the remote monitoring device in response to the occurrence of the predetermined event and transmits the predetermined number of data sets to the remote monitoring device via the communications section in response to a request from the remote monitoring device for a transmission of the predetermined number of data sets. connection terminals for feeding data on an operation state of the mobile work vehicle or vessel; a data storage control section for temporarily storing, in a data storage section at predetermined intervals, only a predetermined number of latest data sets in the data fed via the connection terminals; and a communications section for communication with the remote monitoring device, wherein in response to an occurrence of a predetermined event in the mobile work vehicle or vessel, the data storage control section stores in the data storage section the predetermined number of data sets including a data set obtained upon the occurrence of the predetermined event and transmits the predetermined number of data sets stored in the data storage section, together with information indicating the predetermined event, to the remote monitoring device via the communications section, characterized in that the data storage control section transmits any single one of the predetermined number of data sets stored in the data storage section, as well as the information indicating the predetermined event, to the remote monitoring device in response to the occurrence of the predetermined event and transmits the predetermined number of data sets to the remote monitoring device via the communications section in response to a request from the remote monitoring device for a transmission of the predetermined number of data sets.