Abstract: A dust seal device for a linear guide apparatus includes a pair of side seals and a pair of under seals. The side seal includes a pair of side surface side seals slidably in contact with side surfaces of a guide rail and an upper surface side seal slidably in contact with an upper surface of the guide rail. Each of these side seals has a seal holding plate made of a steel plate, a seal member secured to one long edge of the seal holding plate, and a spring portion formed on the other edge of the holding plate by cutting and bending an end portion of the holding plate. Each of the under seals also includes a holding plate and a seal member, with a spring portion formed in the holding plate. A pair of seal fixing plates are provided so that the side seals and/or the under seals are attached respectively to end caps through the seal fixing plates.