An image forming apparatus includes a groove, an exposure device and an adjustment member. In the groove, an end portion of a rotation shaft of a photosensitive drum is inserted. The exposure device is configured to emit a laser light on the photosensitive drum to form an electrostatic latent image. The adjustment member is configured to shift the end portion of the rotation shaft in a direction other than a vertical direction in the groove to adjust a skew of the laser light.