Provided is an image forming apparatus configured to appropriately determine that an abnormality has occurred in a component. The image forming apparatus includes: a charging device configured to charge a photosensitive drum; an exposure device configured to form an electrostatic latent image on the photosensitive drum charged by the charging device; a developing device including a carrying member configured to carry a toner and being configured to develop the electrostatic latent image using the toner to form a toner image; and a transfer portion configured to transfer the toner image onto a sheet. The image forming apparatus is configured to form a measurement image on the sheet, and to determine a unit that needs to be replaced based on a result of measuring the measurement image formed on the sheet. The measurement image includes a first measurement image and a second measurement image.