A projector includes: a projection position adjusting device that adjusts a projection position of a projection optical device. The projection position adjusting device includes: adjusting and driving units that move a first moving plate and a second moving plate. The adjusting and driving unit include: a pair of worms that have a columnar shape and have threads on outer circumferences thereof; and a pair of sliders that are screwed in the pair of worms, respectively. The pair of worms are disposed to extend along the first direction or the second direction. One of the sliders engages with one of moving plates. Engaging structures including inclining engaging holes that extend in a direction crossing the direction in the plane orthogonal to the projecting direction and engaging projections inserted through the inclining engaging holes are provided in the other slider and the other moving plate.