A laser beam scanning apparatus includes: a laser oscillating unit that outputs a laser beam; a laser beam scanning unit that scans and irradiates the laser beam in a main scanning direction on a photosensitive member; an error signal generating unit that monitors intensity of a laser beam and generates an error signal between output intensity of the laser oscillating unit and a reference value; a correction signal generating unit that generates a correction signal for correcting intensity of a laser beam along the main scanning direction to be constant; a correction signal converting unit that converts a correction signal into an adapted correction signal by attenuating the correction signal; and a laser control signal generating unit that holds, during the image formation period, a reference signal generated on the basis of the error signal and applies the adapted correction signal to the reference signal to generate a laser control signal for determining intensity of a laser beam outputted from the laser oscillating unit.