A roller hemming device comprising: a preliminary bending roller for performing preliminary bending of a work placed on a bottom die; a final bending roller for performing final bending of the work placed on the bottom die; an attachment member to which the preliminary bending roller and the final bending roller are rotatably attached; a supporting member which supports the attachment member; and an arm which is fixed to the supporting member and which sets attitudes of the preliminary bending roller and the final bending roller at desired positions and angles, wherein the attachment member includes a first bent part to which the preliminary bending roller is attached and a second bent part to which the final bending roller is attached, the first bent part being extended downward in an attitude inclined with respect to a vertical direction so as to move into proximity with the work during the preliminary bending and to move out of proximity with the work during the final bending, the second bent part being extended downward in an attitude inclined oppositely to an inclination of the first bent part with respect to the vertical direction so as to move into proximity with the work during the final bending and to move out of proximity with the work during the preliminary bending, the first bent part and the second bent part being arranged at different positions in the vertical direction, the preliminary bending roller is arranged nearer to the work than the first bent part during the preliminary bending, has an axis which is inclined with respect to a horizontal direction so that a processing surface of the preliminary bending roller moves into proximity with the work at the time of the preliminary bending, and is arranged at such a position not to come in contact with the work during the final bending, the final bending roller is formed in a circular truncated cone, is arranged nearer to the work than the second bent part during the final bending, has an axis which is inclined with respect to the horizontal direction so that, during the final bending, a large diameter surface of the final bending roller faces toward the work and a processing surface of the final bending roller is horizontally positioned, and is arranged at such a position not to come in contact with the work during the preliminary bending, and the preliminary bending roller and the final bending roller are arranged along the vertical direction, each having processing point located in a vicinity of an axis of the arm. a preliminary bending roller for performing preliminary bending of a work placed on a bottom die; a final bending roller for performing final bending of the work placed on the bottom die; an attachment member to which the preliminary bending roller and the final bending roller are rotatably attached; a supporting member which supports the attachment member; and an arm which is fixed to the supporting member and which sets attitudes of the preliminary bending roller and the final bending roller at desired positions and angles, wherein the attachment member includes a first bent part to which the preliminary bending roller is attached and a second bent part to which the final bending roller is attached, the first bent part being extended downward in an attitude inclined with respect to a vertical direction so as to move into proximity with the work during the preliminary bending and to move out of proximity with the work during the final bending, the second bent part being extended downward in an attitude inclined oppositely to an inclination of the first bent part with respect to the vertical direction so as to move into proximity with the work during the final bending and to move out of proximity with the work during the preliminary bending, the first bent part and the second bent part being arranged at different positions in the vertical direction, the first bent part being extended downward in an attitude inclined with respect to a vertical direction so as to move into proximity with the work during the preliminary bending and to move out of proximity with the work during the final bending, the second bent part being extended downward in an attitude inclined oppositely to an inclination of the first bent part with respect to the vertical direction so as to move into proximity with the work during the final bending and to move out of proximity with the work during the preliminary bending, the first bent part and the second bent part being arranged at different positions in the vertical direction, the preliminary bending roller is arranged nearer to the work than the first bent part during the preliminary bending, has an axis which is inclined with respect to a horizontal direction so that a processing surface of the preliminary bending roller moves into proximity with the work at the time of the preliminary bending, and is arranged at such a position not to come in contact with the work during the final bending, the final bending roller is formed in a circular truncated cone, is arranged nearer to the work than the second bent part during the final bending, has an axis which is inclined with respect to the horizontal direction so that, during the final bending, a large diameter surface of the final bending roller faces toward the work and a processing surface of the final bending roller is horizontally positioned, and is arranged at such a position not to come in contact with the work during the preliminary bending, and the preliminary bending roller and the final bending roller are arranged along the vertical direction, each having processing point located in a vicinity of an axis of the arm.