A two-stage linked sliding door of a machine tool is provided with a first door half and a second door half movable through different strokes. Pulleys are disposed individually at two opposite end portions of the second door half, and a wire is stretched between the pulleys. The opposite end portions of the wire are secured to the door frame or the first door half by two wire tensioning springs, individually, such that the opposite end portions face each other. These two springs are juxtaposed and offset with each other so that their respective central axes do not line on the same axis.