Abstract: An anti-sliding bar for furnace wall constructions of the type comprising: an open support structure wall and mat means of fibrous insulating material, including U,S,C or the like shaped sections interleaved to each other; anchoring means between the interleaved U,S,C or the like shaped sections, and tying means passing through the mat means, to hold the anchoring means attaching the mat means to the open support structure wall; the anti-sliding bar comprising: a rod supporting the mats, extending horizontally between the U, S,C or the like shaped sections, having: anti-sliding means, fastening tying means for supporting the bar to the mesh means.