According to one embodiment, an image forming apparatus includes an image bearing member, a charging roller, an exposure unit, a developing device, a transfer roller, and a control unit. The charging roller charges the image bearing member. The exposure unit forms an electrostatic latent image on the surface of the image bearing member. The developing device develops the electrostatic latent image formed on the surface of the image bearing member into a toner image. The transfer roller transfers the toner image from the image bearing member. The control unit detects a resistance detection voltage of the transfer roller as a voltage for detecting that there is an abnormality in the image bearing member.