A development device using a developing agent including a toner and a carrier, in which the development device includes a development roller that attaches the developing agent to a circumference surface of the development roller and transfers the developing agent to a development region in which the development roller faces a photo receptor; and a regulation portion to regulate an amount of the developing agent transferred to the development region, where the regulation portion includes first, second, and third regulation portions sequentially disposed in the stated order in an opposite direction to a rotational direction of the development roller, where the first, second, and third regulation portions are respectively spaced apart from the circumference surface of the development roller by first, second, and third intervals, the second interval is greater than the third interval, and the third interval is narrowed in the rotational direction of the development roller.