A developing device includes a developing container, a developing roller, a supplying roller, a first magnetic including a first magnetic pole, a second magnetic including second to fifth magnetic poles, and a regulating member. Maximum magnetic flux densities of the third and fourth magnetic poles are larger than maximum magnetic flux densities of the fourth and fifth magnetic poles, respectively, with respect to a normal direction to the supplying roller. In a case that positions where a magnetic flux density of the fourth magnetic pole is 50% of the maximum magnetic flux density thereof with respect to the normal direction are a first position and a second position, a position where the magnetic flux density of the fourth magnetic pole becomes maximum with respect to the normal direction is downstream of an intermediary position between the first position and the second position by 3 degrees or more.