One or more embodiments may provide a simulator for reproducing, in a virtual space, a motion of a machine that is controlled by a control program to manipulate an object. The simulator includes a processor configured with a simulation program to perform operations including: determining a condition of the object from a real space image; calculating an initial position of a virtual object in the virtual space corresponding to the determined condition; calculating a command value for moving a virtual machine in the virtual space, according to the control program and based on the position of the virtual object manipulated by the virtual machine in the virtual space, wherein the virtual machine corresponds to the machine; and creating display data for displaying one of: a motion of the virtual machine and a motion of the virtual object that are moved in accordance with the calculated command value.