PURPOSE: To simplify the data processing/management and to reduce the cost for control, by calculating a filling time necessary for the filling to a predetermined amount of a master filling station, and opening a fluid valve of a filling element of a subordinate filling station during the duration or the opening time on the basis of the calculated control value.

CONSTITUTION: A controller 41 determines an opening time T' necessary for filling each can 1 by a target filling amount on the basis of the measurement data S1 delivered by a flowmeter 39 through a measurement conductor 40. That is, in a case when the filling station is a master filling station 8M, an amount of liquid filling flowing through the flowmeter 39 is monitored by the controller 41 after a fluid valve is opened, and compared with a predetermined value of the amount of filling to be filled in the can 1. When the amount of filling is agreed with the target value, the fluid valve of the filling element 8 of the master filling station 8M is closed, and the predetermined filling is completed. Whereby a time to achieve the change of a flowing speed of the liquid filling by the filling element 8 can be detected.