An image forming apparatus includes: a photosensitive element; a writing light source; a conveying unit; a light-emitting unit; a detection unit; a writing control unit; and an adjustment unit. The detection unit detects reflected light from a recording medium. The writing control unit controls the writing light source based on operational timing when a signal output from the detection unit turns to a fixed threshold. The adjustment unit acquires information of a gloss level of the recording medium, and adjusts light emission intensity of the light-emitting unit according to the acquired information of the gloss level in such a manner that a signal output from the detection unit when the light-emitting unit irradiates a plain region of the recording medium approximates a certain reference value.