An arm curl fitness apparatus that comprises: a pair of first frames, a second frame, a pair of first rotation bars, a pair of handles, a pair of second rotation bars, a pair of wires, and a pair of armrests; wherein the first frames are each provided standing upright in a straight bar shape; wherein the second frame is formed in a U-shape with each end of the second frame coupled to the upper end of one of the first frames, respectively, and is inclined upwardly toward the rear, wherein the second frame comprises a pair of fixed pulleys formed on parts of the second frame facing each other and protruding outwardly in opposite directions thereon; wherein each first rotation bar is formed shorter than the first frame, and one end of each first rotation bar is rotatably coupled to the upper outer side of one of the first frames, respectively, and disposed downward; wherein each handle is formed in a L-shape with one end of each handle rotatably coupled to one of the first rotation bars, respectively, and the other end of the handle is configured for facing a user and for being gripped by the user; wherein one end of each second rotation bar is rotatably coupled to the lower outer side of one of the first frame, respectively, and the other end of each second rotation bar is fitted with a predetermined weight respectively, and disposed to be inclined downwardly toward the rear; wherein one end of each wire is connected to a point adjacent to one end of one of the first rotation bars, respectively, and the other end of each wire is connected to a point adjacent to the other end of one of the second rotation bars, respectively, while wrapping around an upper side of a respective one of the fixed pulleys; and wherein each armrest is provided on the inside of the upper part of one of the first frames, respectively, for supporting the user's triceps from the rear, wherein each armrest is configured to adjust the angle of inclination to the ground. wherein the first frames are each provided standing upright in a straight bar shape; wherein the second frame is formed in a U-shape with each end of the second frame coupled to the upper end of one of the first frames, respectively, and is inclined upwardly toward the rear, wherein the second frame comprises a pair of fixed pulleys formed on parts of the second frame facing each other and protruding outwardly in opposite directions thereon; wherein each first rotation bar is formed shorter than the first frame, and one end of each first rotation bar is rotatably coupled to the upper outer side of one of the first frames, respectively, and disposed downward; wherein each handle is formed in a L-shape with one end of each handle rotatably coupled to one of the first rotation bars, respectively, and the other end of the handle is configured for facing a user and for being gripped by the user; wherein one end of each second rotation bar is rotatably coupled to the lower outer side of one of the first frame, respectively, and the other end of each second rotation bar is fitted with a predetermined weight respectively, and disposed to be inclined downwardly toward the rear; wherein one end of each wire is connected to a point adjacent to one end of one of the first rotation bars, respectively, and the other end of each wire is connected to a point adjacent to the other end of one of the second rotation bars, respectively, while wrapping around an upper side of a respective one of the fixed pulleys; and wherein each armrest is provided on the inside of the upper part of one of the first frames, respectively, for supporting the user's triceps from the rear, wherein each armrest is configured to adjust the angle of inclination to the ground.