To provide a machine tool cover device which prevents chips from scattering from a machining area to a rear non-machining area, and prevents the chips from depositing on a telescopic cover.

In the machine tool cover device, one end of a curtain-like cover member 11 having flexibility is screwed to a movable column 5, and the other end of the same to a cover mounting member 12 arranged on a machine frame 13, respectively. Further an upper end of the curtain-like cover member 11 is screwed to distortion preventive chains 22L, 22R, and a lower end of the same to a front surface of the X-axial telescopic cover 15, respectively. By virtue of this arrangement, the machining area A is shielded from the non-machining area B, and therefore chips are prevented from scattering. Further by locating the lower portion of the curtain-like cover member 11 on the front of the X-axial telescopic cover 15, chips are prevented from depositing on the X-axial telescopic cover 15.