A multi-beam exposure device reducing variations of electron beam optical systems for electron beams, and preventing vacuum leakage. An exposure device is provided, including: a body tube depressurized to produce a vacuum state therein; multiple charged particle beam sources provided in the body tube, and emitting multiple charged particle beams in a direction of extension of the body tube; multiple electromagnetic optical elements, each provided corresponding to one of the multiple charged particle beams in the body tube, and controlling the one of the multiple charged particle beams; first and second partition walls arranged separately from each other in the direction of extension in the body tube, and forming a non-vacuum space between at least parts of the first and second partition walls; and a supporting unit provided in the body tube, and supporting the multiple electromagnetic optical elements for positioning of the multiple electromagnetic optical elements.