Disclosed is a remote monitoring terminal device 200 including: connection terminals (T, . . . ); a data abridging control section for computing minimum, maximum, and average values of data collected over a period from a startup to a latest data acquisition, and an occurrence count and durations of a predetermined event, all on the basis of data on an operation state acquired via connection terminals (T, . . . ) and stored in a data storage section; and a communications section, wherein the data abridging control section transmits the minimum, maximum, and average values and the occurrence count and durations of the predetermined event, all stored in the data storage section, to a remote monitoring device via the communications section in response to a manual turn-off of a startup switch SW of a mobile work vehicle or vessel.