A machining program is read in and interpreted and a determination is made as to whether the amount of movement called for by a block of commands is larger or smaller than a minimum amount of movement that is established by a feed speed and a one sampling period of a numerical control apparatus. If the amount of movement called for is greater than the minimum amount of movement, feed control is performed in accordance with the current block. If the amount of movement called for by the current block of commands is smaller than the minimum movement amount, an immediate subsequent block of commands is concatenated with the current block, and this concatenation of command blocks is continued until a synthesized block calling for an amount of movement greater than the minimum amount of movement is obtained, this synthesized block then being used to perform feed control.