NOVELTY - An apparatus simulator (2) performs a simulation process as a virtual manufacturing apparatus based on apparatus layout data of manufacturing apparatus and the control command for controlling the manufacturing apparatus as well as the virtual manufacturing apparatus, received from an apparatus controller (3). The simulation results at the virtual manufacturing apparatus in the apparatus simulator, and the manufacturing apparatus are respectively acquired by an equipment engineering system (EES) (4) so as to perform comparison.    USE - System for assisting design manufacture of manufacturing apparatus such as semiconductor manufacturing apparatus, flat-panel manufacturing apparatus, solar cell manufacturing apparatus, etc.    ADVANTAGE - Since the execution result by the apparatus controller is verified by EES, the simulation in each case of an actual commercial installation can be verified based on the objective execution result. The determination of whether the software functions normally can be confirmed before the manufacturing apparatus is assembled by the apparatus design manufacture assistance system, so the period from the design of manufacturing apparatus to the assembly is shortened, and sufficient period allowances are ensured when a malfunction is produced. The simulation can be performed even if a commercial installation does not exit, and higher-precision simulation is attained by performing simulation based on the control command from the apparatus controller.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) apparatus simulator program for apparatus design manufacture assistance system; and    (2) apparatus design manufacture assistance method.    DESCRIPTION OF DRAWING(S) - The drawing shows a block diagram of apparatus design manufacture assistance system (Drawing includes non-English language text).    Apparatus design manufacture assistance system (1)    Apparatus simulator (2)    Apparatus controller (3)    EES (4)    Computer aided system (5)