Abstract: A steam generator includes first and second mutually parallel flue gas flues; the first flue gas flue having an upper end, an intermediate ceiling at the upper end having an upper surface, a cross flue leading from the first to the second flue gas flue, and first and second vertical walls formed of pipes and disposed opposite each other as seen along the cross flue; a steam generator frame supporting the intermediate ceiling; the intermediate ceiling being formed of pipes gas-tightly welded to each other and disposed alongside each other in one layer in tube tracks extended along the cross flue; each of the pipes of the intermediate ceiling changing into a respective pipe of one of the vertical walls; and first and second vertical suspension pipes connected from a common location along a given one of the tube tracks through the upper surface of the intermediate ceiling and through the cross flue to the steam generator frame for suspending the intermediate ceiling, the first suspension pipe changing into a pip