In an absorbing tower including an absorption unit of relatively small diameter capable of absorption and removal by an absorbent slurry for exhaust gas purification and a tank unit of relatively large diameter for temporarily storing the absorbent slurry flowing down from the absorption unit, the tank unit and the absorption unit are joined together by a conical member. By disposing an entrance flue at the conical member, a distance from an upper portion of the conical member to a spray header is shortened, and a height of the absorbing tower can be reduced accordingly. By extending a front end of the entrance flue to the absorption unit into which droplets of the absorbent slurry fall, a high-temperature exhaust gas from a boiler, etc., that has passed through the entrance flue, is made to pass through a circumference of the conical member so that an inexpensive material can be used in the conical member.