A light-exposure device is provided with a microlens array on which is arranged with a prescribed regularity a plurality of microlenses on which exposure light transmitted through a light source and a mask is introduced to resolve an upright equal-magnification image on a substrate. Upon reaching a prescribed position, the substrate is irradiated with pulsed laser light from the light source, and the substrate is successively exposed, and after the entire area of the exposure region of the substrate is exposed, a relative positional relationship between the microlens array and the mask is successively switched in a vertical direction by an amount of a horizontal pitch of the microlenses, and a subsequent exposure is performed. Exposure with high precision and high resolution can thereby be performed with a short exposure cycle time.