Abstract: A movable grate comprising a number of grate steps which are arranged adjacent each other, partly overlap one another and are pivotable around an axis extending in the longitudinal direction of said grate step, and which are pivotably mounted outside shield members (7, 10) which in lateral direction enclose a combustion chamber, end plates (5) being rigidly secured to the ends of the grate steps and swingable therewith, the end plates being aligned with and fitted in openings in the shield members. The novel matter of the invention resides in that portions (10) of the shield members having such openings aligned with the end plates (5), are displaceably mounted relative to adjoining shield members (7) in the direction of the grate step axis, and that the shield portions (10) which outwardly sealingly engage adjoining shield members (7) and inwardly sealingly engage the end plates (5), are in the direction of said axis rigidly secured to the grate step shaft.