A suturing device (10, 100) comprising: first and second holding members (12, 14) configured to move toward and away from each other to sandwich therebetween edges of a cut; a plurality of needles disposed at the first holding member and aligned in a needle arrangement direction with their points pointing to the second holding member, the plurality of needles configured to hold a suture at tips thereof and penetrate the edges of the cut; a needle moving mechanism configured to move the plurality of needles toward the second holding member, thereby allowing the plurality of needles holding the suture at the respective tips to penetrate the edges of the cut; and a suture hook disposed at the second holding member and configured to move along the needle arrangement direction to catch the suture that has reached the second holding member via the edges of the cut by movement of the plurality of needles toward the second holding member by the needle moving mechanism; characterized in that the suturing device further comprises a knot forming jig disposed at a proximal end portion of the second holding member, wherein the suture hook is disposed at the proximal end portion of the second holding member in such a manner to move along the needle arrangement direction, wherein the suture can be wound around the knot forming jig to form a loop in the suture for forming a certain knot, and wherein the suture hook is configured to hold the suture and to pass through between the loop of the wound suture and the knot forming jig to allow the knot forming jig to form the certain knot in the suture held by the suture hook. first and second holding members (12, 14) configured to move toward and away from each other to sandwich therebetween edges of a cut; a plurality of needles disposed at the first holding member and aligned in a needle arrangement direction with their points pointing to the second holding member, the plurality of needles configured to hold a suture at tips thereof and penetrate the edges of the cut; a needle moving mechanism configured to move the plurality of needles toward the second holding member, thereby allowing the plurality of needles holding the suture at the respective tips to penetrate the edges of the cut; and a suture hook disposed at the second holding member and configured to move along the needle arrangement direction to catch the suture that has reached the second holding member via the edges of the cut by movement of the plurality of needles toward the second holding member by the needle moving mechanism; characterized in that the suturing device further comprises a knot forming jig disposed at a proximal end portion of the second holding member, wherein the suture hook is disposed at the proximal end portion of the second holding member in such a manner to move along the needle arrangement direction, wherein the suture can be wound around the knot forming jig to form a loop in the suture for forming a certain knot, and wherein the suture hook is configured to hold the suture and to pass through between the loop of the wound suture and the knot forming jig to allow the knot forming jig to form the certain knot in the suture held by the suture hook.