PURPOSE: To easily detect bugs and to contribute to improvement of generation efficiency by enabling even an unskilled programmer to generate software.

CONSTITUTION: The stage where a display means for display of operation states of plural operation elements of a device is plotted as a two-dimensional drawing on a picture, the stage where flow chart language modules preliminarily generated in each function unit for control of the operation states of operation elements are combined to generate a flow chart language, the stage where a simulator which successively displays operation states of operation elements on the display means is used to verify the flow chart language and removes detected bugs, and the state where a compiler is used to translate the flow chart language where bugs are removed to software constituted in a desired language are provided.