A command value for moving a virtual machine is calculated according to a control program and based on model data of a virtual object (step S313, step S314) where the virtual machine corresponds to a machine and the virtual object is manipulated by the virtual machine in a virtual space and corresponds to an object; motion of the virtual machine which is moved in accordance with the calculated command value is calculated (step S315); motion of the virtual object which is moved in accordance with the calculated motion of the virtual machine (step S315); a virtual space image is generated (step S115) where the virtual space image is assumed to be acquired in the case where the calculated motion of the virtual machine or the calculated motion of the virtual object is virtually photographed; and the command value is calculated further based on the generated virtual space image (step S313, step S314). An integrated simulation of a machine system covering a visual sensor in a real space corresponding to a virtual photographing part can be realized. A test in the case where the visual sensor is used in machine control can be carried out.