An image forming apparatus includes: an image carrier that carries an electrostatic latent image thereon; an electrostatic latent image forming unit that forms an electrostatic latent image on a surface of the image carrier; a developing unit having a toner hopper that receives toner, and a contact portion that contacts with a surface of the image carrier, the contact portion being provided to be displaceable relatively along the surface of the image carrier so as to transfer the toner received in the toner hopper to the electrostatic latent image formed by the electrostatic latent image forming unit; and a guide mechanism that supports the developing unit to be displaceable in a predetermined direction so as to bring the contact portion of the developing unit into contact with an upper portion of the image carrier due to a weight of the developing unit.