An image forming apparatus includes a process cartridge that includes an image bearer including a rotary shaft and rotates about the rotary shaft; a charger to charge a surface of the image bearer; and a developing device to develop an electrostatic latent image formed on the image bearer into a visible toner image. The charger includes a charging roller that rotates about a shaft together with the image bearer during image formation and electrically charges a surface of the image bearer. A surface linear speed of the charging roller is made slower than a surface linear speed of the image bearer. The image forming apparatus includes a charging roller controller that switches the rotational speed of the charging roller to a first rotational speed slower than the linear speed of the image bearer and a second rotational speed identical to the linear speed of the image bearer.