A suture and ligature device for medical treatment comprising: a suture and ligature tool for medical treatment that has a suture and ligature member that is formed by a flexible wire material and that sutures or ligatures biological tissue, a fixing member (21, 60) that is able to move freely backwards and forwards relative to the suture and ligature member and that fixes biological tissue in a state in which the biological tissue is sutured or ligatured by the suture and ligature member, and a holding member through which the suture and ligature member is inserted such that it is able to move freely backwards and forwards and that has at least one aperture portion (24a, 24b) that exposes a portion of the suture and ligature member to the outside; an operating device that has a flexible sheath and a manual operating section; and a cutting member (15, 40, 50, 65) that is provided with a blade portion that is able to make at least one of a forward or backward movement and a rotational movement relatively to the suture and ligature member and that is inclined relative to the forward and backward direction or the rotational direction by an angle (α), and that is configured to cut the suture and ligature member upon this movement, characterized in that the cutting member (15, 40, 50, 65) includes an inclined end portion that is inclined relative to the longitudinal axis of the cutting member (15, 40, 50, 65) by an acute angle (θ) and that is formed at a distal end of the cutting member (15, 40, 50, 65), and wherein the blade portion is provided on the inclined end portion. a suture and ligature tool for medical treatment that has a suture and ligature member that is formed by a flexible wire material and that sutures or ligatures biological tissue, a fixing member (21, 60) that is able to move freely backwards and forwards relative to the suture and ligature member and that fixes biological tissue in a state in which the biological tissue is sutured or ligatured by the suture and ligature member, and a holding member through which the suture and ligature member is inserted such that it is able to move freely backwards and forwards and that has at least one aperture portion (24a, 24b) that exposes a portion of the suture and ligature member to the outside; an operating device that has a flexible sheath and a manual operating section; and a cutting member (15, 40, 50, 65) that is provided with a blade portion that is able to make at least one of a forward or backward movement and a rotational movement relatively to the suture and ligature member and that is inclined relative to the forward and backward direction or the rotational direction by an angle (α), and that is configured to cut the suture and ligature member upon this movement, the cutting member (15, 40, 50, 65) includes an inclined end portion that is inclined relative to the longitudinal axis of the cutting member (15, 40, 50, 65) by an acute angle (θ) and that is formed at a distal end of the cutting member (15, 40, 50, 65), and wherein the blade portion is provided on the inclined end portion. an inclined end portion that is inclined relative to the longitudinal axis of the cutting member (15, 40, 50, 65) by an acute angle (θ) and that is formed at a distal end of the cutting member (15, 40, 50, 65), and wherein the blade portion is provided on the inclined end portion.