PURPOSE: To machine up to near a headstock by providing a plurality of telescopic metal plates capable of moving in the notch of a headstock located between the headstock and a bed guide continuously from one slider system to another slider system.

CONSTITUTION: A headstock 2 is installed on a machine bed 1, and slider systems 4 and 5 capable of traveling on bed guides 3 located on both sides of the headstock are provided. A plurality of telescopic metal plates 6 which run in a guide 7 and engages with each other are provided so as to protect the bed guide 3 and spindles within its range from being cut off. The telescopic metal plates 6 form a metal plate bundle capable of being inserted and extracted telescopically, and their first and last metal plates are connected to slider systems 4 and 5, respectively. Thus, the continuous metal plate bundle capable of moving along the headstock 2 is produced, the slider systems 4 and 5 can be run up to near the headstock 2, and thus a workpiece can be machined to a fixed position on the headstock 2.