An image forming apparatus includes: an array of m light-emitting elements extending in a main scanning direction, the m being an integer satisfying m≧3; a memory that stores a cumulative light emission time of each of the m light-emitting elements; a light intensity adjusting portion that obtains a light intensity adjusting value for the each light-emitting element; an activating portion that controls the activation and deactivation of the each light-emitting element with the light intensity adjusting value; and a selecting portion that selects n light-emitting elements from an end of the array, the n being an integer satisfying n≧2 and n