A suction device 10 according to the present invention has: an outer tube 36 connected to a fluid supply unit 20 on a base-end side thereof and including an opening edge section 37 and a suction tube 38 provided in the outer tube 36 and connected to a negative pressure generating unit 26 on a base-end side thereof, the suction tube 38 including an opening edge section 39, wherein an annular fluid supply passage 40 is formed between an inner peripheral surface of the outer tube 36 and an outer peripheral surface of the suction tube 38, and the opening edge section 39 of the suction tube 38 is placed inside the opening edge section 37 of the outer tube 36 toward the base-end side thereof.
