Apart orienting system for feeding, in a same direction, front surfaces of a plurality of parts that are fed, the system comprising: an introduction passage through which the parts pass; a branching region located downstream of the introduction passage, the branching region including a first branch passage through which parts facing up pass, and a second branch passage through which parts facing down pass, and orienting, into the same direction, the front surfaces of the parts that have passed through the first and second branch passages (40a, 40b); a merge point located downstream of the branching region, the merge point allowing the first branch passage and the second branch passage to merge; and a determining and sorting unit between the introduction passage and the branching region, and configured to determine whether the parts at rest are facing up or down and to feed parts determined as facing up to the first branch passage and parts determined as facing down to the second branch passage characterized in that the parts determined as facing up are sequentially fed to a first branching region, whereas the parts determined as facing down are sequentially fed to a second branching region, wherein the parts can be intermittently fed to the first or second branching region so as to reduce the collision between the parts at the merge point, the part orienting system being configured to orientate parts having a front surface portion that is flat, and a back surface including a back surface portion that is flat and a projection on an outer peripheral edge of the back surface portion, such as a nut, and the determining and sorting unit includes a holder configured to hold each of the parts with the front surface and the back surface facing in a direction orthogonal to a path of the parts, the holder including an abutting surface configured to abut on the front surface or the back surface of each of the parts, is configured to detect a first distance from the abutting surface to the front surface portion of the part if the projection of the back surface portion of the part abuts on the abutting surface, or a second distance from the abutting surface to the back surface portion of the part if the front surface portion of the part abuts on the abutting surface, and is configured to sort and feed, to the first branch passage, parts whose first distance has been detected and, to the second branch passage, parts whose second distance has been detected. an introduction passage through which the parts pass; a branching region located downstream of the introduction passage, the branching region including a first branch passage through which parts facing up pass, and a second branch passage through which parts facing down pass, and orienting, into the same direction, the front surfaces of the parts that have passed through the first and second branch passages (40a, 40b); a merge point located downstream of the branching region, the merge point allowing the first branch passage and the second branch passage to merge; and a determining and sorting unit between the introduction passage and the branching region, and configured to determine whether the parts at rest are facing up or down and to feed parts determined as facing up to the first branch passage and parts determined as facing down to the second branch passage characterized in that the parts determined as facing up are sequentially fed to a first branching region, whereas the parts determined as facing down are sequentially fed to a second branching region, wherein the parts can be intermittently fed to the first or second branching region so as to reduce the collision between the parts at the merge point, the part orienting system being configured to orientate parts having a front surface portion that is flat, and a back surface including a back surface portion that is flat and a projection on an outer peripheral edge of the back surface portion, such as a nut, and the determining and sorting unit includes a holder configured to hold each of the parts with the front surface and the back surface facing in a direction orthogonal to a path of the parts, the holder including an abutting surface configured to abut on the front surface or the back surface of each of the parts, is configured to detect a first distance from the abutting surface to the front surface portion of the part if the projection of the back surface portion of the part abuts on the abutting surface, or a second distance from the abutting surface to the back surface portion of the part if the front surface portion of the part abuts on the abutting surface, and is configured to sort and feed, to the first branch passage, parts whose first distance has been detected and, to the second branch passage, parts whose second distance has been detected. includes a holder configured to hold each of the parts with the front surface and the back surface facing in a direction orthogonal to a path of the parts, the holder including an abutting surface configured to abut on the front surface or the back surface of each of the parts, is configured to detect a first distance from the abutting surface to the front surface portion of the part if the projection of the back surface portion of the part abuts on the abutting surface, or a second distance from the abutting surface to the back surface portion of the part if the front surface portion of the part abuts on the abutting surface, and is configured to sort and feed, to the first branch passage, parts whose first distance has been detected and, to the second branch passage, parts whose second distance has been detected.