To provide a stop time summing up system of equipment capable of accurately summing up stop time depending on respective stop reasons of the equipment without relying on human labor.

The equipment 1 and a computer 2 are mutually connected through LAN 3, and the equipment 1 has a function for communicating the information related to stop time and stop reason to the computer 2 when it stops by manual operation and an error and for communicating restart time to the computer 2 when operation is restarted. The computer 2 computes stop time of the equipment based on the information informed by the equipment 1, stores by corresponding computed stop time to stop reason, and sums up stop time of the equipment depending on stop reason based on the stored information to display the results of SUMMING UP.