A polarized light irradiation apparatus includes: a light source unit including a light source, and emitting parallel light derived from the light source; a polarizing plate for polarizing the parallel light emitted from the light source unit to output polarized light; a polarizing plate holder for holding the polarizing plate; a mask holder for holding a mask having a light transmissive part and a light shielding part; a work stage for holding a work that is irradiated with light that has been polarized by the polarizing plate and has passed the mask; a polarization direction changer for changing a direction of a polarization axis of light for irradiating the work held by the work stage; and an irradiation location changer for changing a location of the polarized light that irradiates the work.