A cab sliding device of an industrial machine, in which a slide base can be inserted into and withdrawn from rails from above the rails, whereby the number of man-hours for assembly can be decreased, and the ease of maintenance can be increased, is provided. For this purpose, in an industrial machine having a cab (11) slidably installed via a slide base (20) on a pair of rails (10) laid on a frame (4), the rails are nearly channel-shaped in cross section, and are provided to have concave space portions (10a) opposed to each other, the slide base has a plurality of rollers (21) annexed to opposite side surface portions thereof, the rollers being rollable inside the concave space portions of the rails, upper surfaces of the rails are provided with openings (12) which permit incoming and outgoing of the roller portions, and the slide base can be inserted into and withdrawn from the rails via the openings from above the rails.