Provided is an acidic-gas treatment agent in which sodium hydrogen carbonate is used as a neutralizer for an acidic gas, wherein the acidic-gas treatment agent tends not to form into a cake and has exceptional peeling properties. The acidic-gas treatment agent contains sodium hydrogen carbonate and an anticaking agent for the sodium hydrogen carbonate, the anticaking agent in the acidic-gas treatment agent being carbon black and/or hydrophobic silica. The content of the anticaking agent is preferably 0.1-2.0 wt%. The average grain size of the hydrophobic silica is preferably 1−20 μm, and the average grain size of the carbon black is preferably 0.1−10 μm.
