PROBLEM TO BE SOLVED: To provide a gas treatment device that has high treatment efficiency by increasing the chance of contact of a filter with a catalyst in a limited space.SOLUTION: A gas treatment device comprises a first electrode, a second electrode that faces the first electrode, and dielectrics that cover opposing surfaces of the first and second electrodes, respectively, and further comprises a plasma generation part that generates plasma between both the electrodes, a meandering passage that is formed between both the electrodes and through which a gas to be treated introduced between both the electrodes flows, and a catalyst body that is arranged inside the passage and to which a catalyst for promoting the decomposition reaction of the gas to be treated is fixed.
