To provide a data control system of a construction machine which can efficienly guarantee a service meter time or the like even when some troubles arise in the data control device of the construction machine.

This data control device 1 is provided with an operational function 2 operating a service meter time or the like, a non-volatile memory function 3 storing the operated data, and a transmitting function 5 transmitting data stored in the memory function 3 to a monitor panel 6. The monitor panel 6 is provided with a non-volatile memory function 7 storing the data received from the data control device 1 as backup data.