Exposure device and image forming apparatus including exposure device

An exposure device that exposes an exposure target member, the exposure device comprising:

• a substrate having flexibility and a sheet-like shape and including one main surface on which a plurality of light-emitting elements are arranged in a substantially linear shape;
• a support member being provided on the other main surface side of the substrate;
• and
• an optical holding member holding an optical member formed of a plurality of lenses that image light emitted from the plurality of light-emitting elements onto the exposure target member, and being provided on the one main surface side of the substrate while a longitudinal direction of the optical member extends along an array direction of the plurality of light-emitting elements, wherein
• the optical holding member is positioned at the support member while sandwiching the substrate between the support member and the optical holding member, and
• a first positioning portion that positions the optical holding member with respect to the exposure target member and a second positioning portion that positions the optical holding member with respect to the support member are provided to the optical holding member at positions outward of both ends of the optical member in the longitudinal direction of the optical member.