Abstract: A semiconductor device production method of the present invention first collects data including an initial volume of plating solution, volume of replenished solution, number of wafers processed, value of current applied and volume of waste solution in a step of filling a metal plating film in a via hole or a trench formed in an insulating film on a semiconductor substrate. Then, a cumulative charge during the plating is calculated based on the obtained current value. Also, a total volume of plating solution is calculated. Furthermore, an amount of decomposition products of suppressors contained in the plating solution based on the calculated total volume of plating solution, the volume of waste solution and the calculated cumulative charge. The semiconductor substrate is plated only when the amount of decomposition products is equal to or smaller than a predetermined threshold.