To provide a suction device which is high in speed, excellent in durability and has reduced noise.

The suction device is provided with rotary shielding plates 34a, 34b, 34c which are rotationally driven with a servomotor without contacting with a cylindrical body 20 and, when a part 10a in which fins are formed is entered a suction port 22, the part 10a in which the fins are formed is sucked to the suction port 22 by interrupting the suction of air from opening parts 24, 24 and, when the part 10a in which the fins are formed is sucked to the suction port 22 is formed into a fin F for heat exchangers, air is sucked from the opening parts 24, 24 and the fin F for heat exchangers are discharged to a stacking device. A control part for controlling the servomotor is provided so that, when the part 10a in which the fins are formed is entered the suction port 22, the rotary shielding plates 34a, 34b, 34c are in the suction position and, when it is cut into the fin F for heat exchangers, the rotary shielding plates 34a, 34b, 34c are in a discharging position.