A method for removing hydrogen chloride from an exhaust gas discharged from an incinerator, which comprises the steps of: causing hydrogen chloride contained in an exhaust gas discharged from an incinerator to react with slaked lime in slurry to form basic calcium chloride; detecting a concentration (y) of hydrogen chloride remaining in the exhaust gas after the reaction with slaked lime; determining a deviation (.DELTA.y) of the thus detected concentration (y) of hydrogen chloride from a target concentration (y.sub.o) thereof; determining a corrected deviation (.DELTA.y') by adding to the above-mentioned deviation (.DELTA.y) a correction value (.DELTA.y.sub.1) calculated in accordance with the following formulae:.DELTA.y.sub.1 =-G.sub. p(S)(1-e.sup.- LS)U (1).DELTA.y'=.DELTA.y+.DELTA.y.sub.1 (2)where,G.sub.p (S): a transfer function representing a first order lag,e.sup.-i LS : a transfer function representing a dead time, andU: a target amount of supply of slaked lime, which renders the deviation (.DELTA.y) zero;determining a target amount of supply (U) of slaked lime, which renders the thus determined corrected deviation (.DELTA.y') zero; and adjusting an amount of supply of slaked lime so that the amount of supply of slaked lime agrees with the thus determined target amount of supply (U) of slaked lime; thereby removing hydrogen chloride from the exhaust gas discharged from the incinerator.