A stroke time of a piston from excitation of a solenoid valve for driving the piston of a pneumatic cylinder to arrival at an end position thereof and a velocity of the piston at the arrival of the piston at the end position are determined by a simulation calculating unit for several load rates of the pneumatic cylinder for a plurality of determined combinations of the solenoid valve, a speed controller, the pneumatic cylinder, and tubes for connecting therebetween. The stroke time and velocity of the piston determined by the simulation calculating unit for each of the load rates for each of the plurality of combinations are displayed in a superimposed manner on a display unit with a display control means based on a stroke of the pneumatic cylinder.