Abstract: In a device for causing contact between horizontally-flowing gas and vertically-flowing liquid, a stack of corrugated contact plates in face-to-face contact and having their corrugations inclined to the horizontal plane. Alternate plates of the stack are inclined upwardly in the direction of gas flow and the intermediate plates are inclined downwardly at the same angle of inclination. The upwardly-inclined corrugations have a smaller radius of curvature than the downwardly inclined corrugations. The heights of the respective corrugations are preferably equal and the radius of curvature in the upwardly-inclined corrugations is less than the height of said corrugations.