A suction device, comprising: a swirl-flow forming body including a columnar main body having a flat end face, a concave part formed at the flat end face, and a supply port through which fluid is supplied to the main body, wherein the columnar main body has an inner-peripheral side surface arranged to face the concave part and is tapered such that the diameter of the concave part enlarges toward an opening, the swirl-flow forming body further includes jetting ports formed on an inner peripheral side surface facing the concave part and, when in use, fluid is discharged into the concave part via the jetting ports, and at least two fluid flow forming means, each of which is arranged in communication with a respective jetting port, such that in operation each of the fluid-flow forming means forms a swirl flow of fluid within the concave part; a case being a housing member for housing the swirl-flow forming body and for guiding fluid flowing out of the concave part of the swirl-flow forming body, the case includes a guide part, wherein the guide part is a cylindrical member having an opening edge and arranged to surround the concave part and the opening edge projects toward a material relative to the flat end face of the swirl flow-forming body to allow flow of fluid out of the concave part and along the flat end face in a direction away from a position occupied by the material prior to commencement of the suction; wherein an inner periphery of the guide part is tapered such that an inner diameter of the guide part reduces toward the opening edge, and the guide part is arranged to guide the fluid out of concave part along the inner periphery; and wherein in operation the swirl-flow forming body discharges fluid into the concave part to generate negative pressure within the concave part, which negative pressure applies suction to the material. a swirl-flow forming body including a columnar main body having a flat end face, a concave part formed at the flat end face, and a supply port through which fluid is supplied to the main body, wherein the columnar main body has an inner-peripheral side surface arranged to face the concave part and is tapered such that the diameter of the concave part enlarges toward an opening, the swirl-flow forming body further includes jetting ports formed on an inner peripheral side surface facing the concave part and, when in use, fluid is discharged into the concave part via the jetting ports, and at least two fluid flow forming means, each of which is arranged in communication with a respective jetting port, such that in operation each of the fluid-flow forming means forms a swirl flow of fluid within the concave part; a case being a housing member for housing the swirl-flow forming body and for guiding fluid flowing out of the concave part of the swirl-flow forming body, the case includes a guide part, wherein the guide part is a cylindrical member having an opening edge and arranged to surround the concave part and the opening edge projects toward a material relative to the flat end face of the swirl flow-forming body to allow flow of fluid out of the concave part and along the flat end face in a direction away from a position occupied by the material prior to commencement of the suction; wherein an inner periphery of the guide part is tapered such that an inner diameter of the guide part reduces toward the opening edge, and the guide part is arranged to guide the fluid out of concave part along the inner periphery; and wherein in operation the swirl-flow forming body discharges fluid into the concave part to generate negative pressure within the concave part, which negative pressure applies suction to the material.