An air intake and blowout tool comprising a cylinder body that includes along a cylinder-central axis (C1) an air passage having an air intake port on one end and an air blowout port on another end, and, in a midsection of the cylinder body , a compressed air introduction part capable of introducing compressed air into the air passage , the compressed air introduction part configured to introduce compressed air into the air passage toward an air blowout port side of the air passage to generate negative pressure in the air passage on an air intake port side thereof and thereby produce an air flow in the air passage , and thus providing air being sucked from the air intake port into the air passage and blown out from the air blowout port , wherein: the compressed air introduction part includes a compressed air exit port formed in a shape of ring that extends circumferentially about the cylinder-central axis, and slot-shaped extending straight along a radial direction of the cylinder body to open into the air passage , the air passage forming inner circumferential surface of the cylinder body on an air blowout port side of the compressed air exit port includes an annular protuberance surface portion protruding toward a radially inner side of the cylinder body greater than an air passage forming inner circumferential surface on an air intake port side of the compressed air exit port , and extending circumferentially about the cylinder central axis (C1), the annular protuberance surface portion includes a protuberance surface shaped to extend from a peripheral edge portion of the air blowout port side of the compressed air exit port toward the radially inner side of the cylinder body and to then gradually curve and extend toward the air blowout port side, characterized in that the air passage forming inner circumferential surface of the cylinder body on the air intake port side of the compressed air exit port includes an annular stepped surface portion extending along a peripheral edge portion of the air intake port side of the compressed air exit port . the compressed air introduction part includes a compressed air exit port formed in a shape of ring that extends circumferentially about the cylinder-central axis, and slot-shaped extending straight along a radial direction of the cylinder body to open into the air passage , the air passage forming inner circumferential surface of the cylinder body on an air blowout port side of the compressed air exit port includes an annular protuberance surface portion protruding toward a radially inner side of the cylinder body greater than an air passage forming inner circumferential surface on an air intake port side of the compressed air exit port , and extending circumferentially about the cylinder central axis (C1), the annular protuberance surface portion includes a protuberance surface shaped to extend from a peripheral edge portion of the air blowout port side of the compressed air exit port toward the radially inner side of the cylinder body and to then gradually curve and extend toward the air blowout port side, characterized in that the air passage forming inner circumferential surface of the cylinder body on the air intake port side of the compressed air exit port includes an annular stepped surface portion extending along a peripheral edge portion of the air intake port side of the compressed air exit port . <EOS>