PURPOSE: To provide a joint work device which can report the oprations of the joint workers, can select the sure report information, can designate a reporting method and can have a real-time previous arrangement, respectively.

CONSTITUTION: A joint work device is provided with a shared data monitoring means 3 which monitors the opration of each worker to the shared data, a reporting level information storing means 9 which stores the reporting level information that decides a mode for reporting the opration of a certain worker given to the shared data to other workers, a reporting information production means 4 which produces the reporting information based on both information given from the means 3 and the means 9, a reporting information decoding means 5 which decodes the received reporting information and decides a reporting mode accordant with the reporting level including the trporting information and a reporting information display means 6 and a reporting information storing means 7 which give the reporting information to the workers based on the reporting mode decided by the means 5.