A development unit includes a toner carrying device, a regulating member, and a toner leak protection member. The toner carrying device having a first electrode and a second electrode arrayed with an interval. The first and second electrodes are supplied with a given voltage to set an electric field, changing in a time cycle, between the first and second electrodes. The electric field is used to hop toner over the toner carrying device to form a toner cloud for developing a latent image. The regulating member regulates an amount of toner on the toner carrying device. The toner leak protection member, made from a conductive material, prevents leakage of toner, and is supplied with a bias voltage.