An apparatus for and method of forming images. The apparatus includes a photosensitive member, a charging member configured to electrify a surface of the photosensitive member to a predetermined electric potential, an exposure member configured to form an electrostatic latent image on the electrified surface of the photosensitive member, and a developing member configured to develop a toner image on the surface of the photosensitive member on which the electrostatic latent image is formed. The developing member converts a toner disposed near the photosensitive member into a cloud state using ultrasonic oscillation and adheres the cloud-state toner to the electrostatic latent image due to a bias voltage applied between the developing member and the photosensitive member.