A method and an apparatus for numerical control to automatically and repetitively carry out numerical control in compliance with a numerical control program modified by utilizing an override function. Whether a teaching instruction is input or not is discriminated (S1) while a numerical control program is being executed. When it is determined (S2, S6) that the feed speed or the main axis speed override memory instruction is input in the teaching mode, an override value set manually using an override switch is written (S10) onto the end of a block under execution of the numerical control program. When the numerical control program is executed on the next time and thereafter, the override operation is automatically carried out as set manually.