To provide a means which can easily attach a dustproofing cover without removing mounting screws fixing a side seal or end cap to a slider, and improve space utility controlling the dustproofing cover.

The dustproofing cover arranged in a linear guide apparatus 1 comprises: a slider side attachment 20 fixed in a slider 7 which is formed in a different portion; a sliding panel 50 which has an inner side profile 54 along a crosssectional shape of rail 2, and is arranged in an axial direction of the rail 2; a slider side mounting panel 30 which is fitted in the slider side attachment 20, and mounted to the slider side attachment 20 with a first engaging portion consisting of engaging piece 27 and engaging hole 37; and a bellows 60 which is fitted in the sliding panel 50, and joined with a sliding panel attachment 40 attached to the sliding panel 50 with a second engaging portion consisting of an engaging piece 47 and engaging hole 57.