The present invention relates to an apparatus for preventing, in a multi-stage dryer for drying coal using reheat steam, spontaneous ignition caused by oxidation of coal when coal is transferred to the multi-stage dryer from a fixed quantity coal supplier by way of a pulverizer. The present invention relates to an apparatus for drying coal using reheat steam, the apparatus being configured so that coal which has been dried primarily in a first coal dryer is inputted into a second coal dryer and thus is secondarily dried, wherein reheat steam generated from a reheater is supplied through a reheat steam supply pipe; a nitrogen supplier supplies nitrogen through a nitrogen supply pipe; saturated steam generated from a saturated steam generator is supplied through a saturated steam supply pipe; the reheat steam supply pipe, the nitrogen supplier, and the saturated steam supply pipe are connected to a 4-way valve; and the 4-way valve supplies nitrogen and saturated steam, or nitrogen or saturated steam, along with