A swirling flow generator for gas-liquid separation for separating a liquid and a gas from gas-liquid two-phase fluid by centrifugal force, the swirling flow generator comprising: a swirling flow generating ribbon (30, 50) for swirling the gas-liquid two-phase fluid, the swirling flow generating ribbon (30, 50) formed from a helically twisted plate member; and a pipe (21, 41) that receives the swirling flow generating ribbon (30, 50) and comprises an inner surface to which a separated liquid is guided, wherein the swirling flow generating ribbon (30, 50) comprises, in a terminal end at a side where the gas-liquid two-phase fluid flows out, a first terminal end point that is in a first end of radially outward ends of the swirling flow generating ribbon (30, 50); a second terminal end point that is in a second end of radially outward ends of the swirling flow generating ribbon (30, 50); a middle terminal end point that is on an axial line of the swirling flow generating ribbon (30, 50) and at a location closer to a side where the gas-liquid two-phase fluid flows in the swirling flow generating ribbon (30, 50) than the first terminal end point and the second terminal end point; a terminal line between the first terminal end point and the second terminal end point is perpendicular to the axial line of the swirling flow generating ribbon; a first terminal edge connecting the first terminal end point and the middle terminal end point; a second terminal edge connecting the second terminal end point and the middle terminal end point, characterized in that in the terminal end of the swirling flow generating ribbon, a V shaped space or area is defined by the first terminal edge, the second terminal edge, and the terminal line, wherein the swirling flow generating ribbon (30, 50) comprises a folding back structure in the first terminal edge and the second terminal edge, the folding back structure being folded back toward the side where the gas-liquid two-phase fluid flows in the swirling flow generating ribbon (30, 50). a swirling flow generating ribbon (30, 50) for swirling the gas-liquid two-phase fluid, the swirling flow generating ribbon (30, 50) formed from a helically twisted plate member; and a pipe (21, 41) that receives the swirling flow generating ribbon (30, 50) and comprises an inner surface to which a separated liquid is guided, wherein the swirling flow generating ribbon (30, 50) comprises, in a terminal end at a side where the gas-liquid two-phase fluid flows out, a first terminal end point that is in a first end of radially outward ends of the swirling flow generating ribbon (30, 50); a second terminal end point that is in a second end of radially outward ends of the swirling flow generating ribbon (30, 50); a middle terminal end point that is on an axial line of the swirling flow generating ribbon (30, 50) and at a location closer to a side where the gas-liquid two-phase fluid flows in the swirling flow generating ribbon (30, 50) than the first terminal end point and the second terminal end point; a terminal line between the first terminal end point and the second terminal end point is perpendicular to the axial line of the swirling flow generating ribbon; a first terminal edge connecting the first terminal end point and the middle terminal end point; a second terminal edge connecting the second terminal end point and the middle terminal end point, characterized in that in the terminal end of the swirling flow generating ribbon, a V shaped space or area is defined by the first terminal edge, the second terminal edge, and the terminal line, wherein the swirling flow generating ribbon (30, 50) comprises a folding back structure in the first terminal edge and the second terminal edge, the folding back structure being folded back toward the side where the gas-liquid two-phase fluid flows in the swirling flow generating ribbon (30, 50).