Abstract: An apparatus of clarifying and circulating hot air for heat-treating textile fabric, comprises (A) a heating chamber having a plurality of components connected to each other and partitioned into a hot air-conditioning upper chamber and a fabric-treating lower chamber in which a fabric-passing space is formed and in each compartment, a hot air nozzle means is connected to the fabric-passing space, (B) a hot air-circulation flue extending through the compartments of the hot air-conditioning upper chamber and connected to the hot air nozzle means, (C) a hot air-exhaust flue has exhaust air suction ports connected to the fabric-passing space, and (D) at least one hot air-clarifying box located in the front half portion of the hot air-conditioning upper chamber, having a hot air heater and an oxidizing catalyst layer located therein and connected to the hot air-circulation flue through a hot air-distributing duct and to the hot air-exhaust duct.