To provide an exposure device using light such as EUV light and capable of adjusting positioning on the illumination side without being complicated.

The exposure device includes: an illumination optical system (IL) for illuminating a reflection type mask (M) with light from a light source (1); a projection optical system (PL) for projecting a pattern of the mask onto a photosensitive substrate (W); a reflection mirror (3) located in an optical path between the illumination optical system and the mask for deflecting the light from the illumination optical system to the mask; and an adjusting mechanism (11, 12) for adjusting at least one of the position and the direction of the reflection surface of the reflection mirror.