An aspect of the present invention provides a method of carrying out a simulation with simulation data, including, determining whether or not the simulation data includes boundary conditions set for a boundary of a calculation area set for the simulation, computing the influence of the boundary conditions on the inside of the calculation area if the simulation data includes the boundary conditions, displaying the influence of the boundary conditions on the inside of the calculation area, prompting to enter an instruction whether or not the boundary conditions are changed, and if an instruction to make no change in the boundary conditions is entered, carrying out the simulation with the simulation data.