A developing device including a developing sleeve installed in a developing chamber and partially exposed to an outside of the developing chamber through an opening portion, a magnetic member located inside a developing sleeve and including a separating pole and a receiving pole, the separating pole being located on a downstream side of the opening portion based on a rotating direction of the developing sleeve to separate a developing agent from the developing sleeve, and the receiving pole being located on a downstream side of the separating pole to attach the developing agent to the developing sleeve, and a magnet located between an inner wall of the developing chamber and the magnetic member to face a region between the separating pole and the receiving pole and having same magnetic polarity same as the separating pole and the receiving pole.