A stapler comprising: a magazine unit including a magazine in which staples are loaded; a driver unit including a driver configured to discharge the staples accommodated in the magazine; and a clincher unit (2A, 2B) configured to bend legs of the staple discharged by the driver unit and having penetrated sheets, wherein the clincher unit (2A, 2B) includes: a pair of clinchers (20L, 20R) configured to respectively bend two legs of the staple; a clincher driving mechanism (21, 22L, 22R, 23) configured to rotate and move the clinchers (20L, 20R) in separating/contacting directions, and wherein the clincher driving mechanism (21, 22L, 22R, 23,) is configured to move the pair of clinchers (20L, 20R,) in an approaching direction to each other, so as to bend the legs of the staple having penetrated the sheets, whereby the clincher driving mechanism includes: a pair of clincher links (22L, 22R) that guides a rotation and a movement of the clinchers (20L, 20R) in the separating/contacting directions; and a clincher support part configured to push up the clinchers (20L, 20R) by a descent operation of the clinchers, characterized in that, the clincher driving mechanism includes a clincher holder having a pair of guide holes (21L, 21R) supporting the pair of clinchers (20L, 20R) so that the clinchers can be rotated and moved in the separating/contacting directions, and wherein the clinchers (20L, 20R) move along the pair of guide holes (21L, 21R) by an ascent and descent operation of the clincher holder. a magazine unit including a magazine in which staples are loaded; a driver unit including a driver configured to discharge the staples accommodated in the magazine; and a clincher unit (2A, 2B) configured to bend legs of the staple discharged by the driver unit and having penetrated sheets, wherein the clincher unit (2A, 2B) includes: a pair of clinchers (20L, 20R) configured to respectively bend two legs of the staple; a clincher driving mechanism (21, 22L, 22R, 23) configured to rotate and move the clinchers (20L, 20R) in separating/contacting directions, and a pair of clinchers (20L, 20R) configured to respectively bend two legs of the staple; a clincher driving mechanism (21, 22L, 22R, 23) configured to rotate and move the clinchers (20L, 20R) in separating/contacting directions, and wherein the clincher driving mechanism (21, 22L, 22R, 23,) is configured to move the pair of clinchers (20L, 20R,) in an approaching direction to each other, so as to bend the legs of the staple having penetrated the sheets, whereby the clincher driving mechanism includes: a pair of clincher links (22L, 22R) that guides a rotation and a movement of the clinchers (20L, 20R) in the separating/contacting directions; and a clincher support part configured to push up the clinchers (20L, 20R) by a descent operation of the clinchers, characterized in that, the clincher driving mechanism includes a clincher holder having a pair of guide holes (21L, 21R) supporting the pair of clinchers (20L, 20R) so that the clinchers can be rotated and moved in the separating/contacting directions, and wherein the clinchers (20L, 20R) move along the pair of guide holes (21L, 21R) by an ascent and descent operation of the clincher holder. a pair of clincher links (22L, 22R) that guides a rotation and a movement of the clinchers (20L, 20R) in the separating/contacting directions; and a clincher support part configured to push up the clinchers (20L, 20R) by a descent operation of the clinchers, characterized in that, the clincher driving mechanism includes a clincher holder having a pair of guide holes (21L, 21R) supporting the pair of clinchers (20L, 20R) so that the clinchers can be rotated and moved in the separating/contacting directions, and wherein the clinchers (20L, 20R) move along the pair of guide holes (21L, 21R) by an ascent and descent operation of the clincher holder.