A developing device includes a sleeve and a magnet roller having first and second magnetic poles, the second magnetic pole being disposed downstream of the first magnetic pole. A magnetic attraction distribution on the sleeve in a region from the first magnetic pole to the second magnetic pole is such that the magnetic attraction decreases from a position of the first magnetic pole toward the downstream side, a gradient of change in the magnetic attraction decreases in a region downstream of a region in which a gradient of reduction in the magnetic attraction temporarily increases, thereby forming an attraction reduction region in which the magnetic attraction is reduced so that developer cannot be held on the sleeve, and the gradient of change in the magnetic attraction increases in a region downstream of the attraction reduction region so that the magnetic attraction increases to a position of the second magnetic pole.