PURPOSE: To sharply reduce the memory part of an NC device by providing a file server which can transfer a machining program and machining information for only one block unit on demands from plural NC devices, in an FMS.

CONSTITUTION: A file server 20 is connected to an external auxiliary memory 5 while also connected to plural NC devices 2AW2Z. The captioned system is being changed from a host computer controlled type to an NC device controlled type. Thereby, when the NC device makes a demand immediately before machining, the machining program and machining information for each one block for which actual machining is about to be carried out, are read in the RAM area of each of the NC devices 2AW2Z from the file server 20. That is, the NC devices 2AW2Z can only be fed with a program presently being under way, without need for being fed with the whole programs. Accordingly, a RAM area for one block size suffices eliminating the need for using the RAM area for one program size, sharply reducing a memory part.