1. A digital controlling device for controlling a section comprising means for executing arithmetic operations under control of a predetermined program on the basis of an input signal obtained from at least one detector in a section to be controlled to generate a driving signal and means for sending said driving signal to actuating means in said section to be controlled; said arithmetic operation executing means comprising: (a) first rewritable and non-volatile means storing a plurality of calculation specification tables designating a type of arithmetic operation necessary to be executed, storage addresses of input/output data required for said designated arithmetic operation, and storage addresses of operation parameters required for said designated arithmetic operation; (b) second rewritable and non-volatile means storing a calculation sequence table designating leading addresses of said calculation specification tables stored in said first means which are used for reading-out of said first means the calculation specification tables corresponding to said required arithmetic operations in a predetermined order for those arithmetic operations which are to be executed; (c) third means storing data tables including data and operation parameters in corresponding address areas thereof as specified by the storage addresses in said calculation specification tables designated by said calculation sequence table; and (d) processing program means, including means for storing a plurality of programs to be specified by said arithmetic operation types for executing said arithmetic operations in said predetermined order designated in said calculation sequence table and for reading data and operation parameters necessary for said execution of arithmetic operations from said data tables stored by said third means on the basis of designated ones of said calculation specification tables.