Projector

A projector 1 has a first casing 1A (including a first part 2 and a second part 3) and a second casing 1B (including a third part 4). The second casing 1B is moved between an enlarging position where the second casing 1B is protruded from the first casing 1A and a reducing position where the second casing 1B is retracted into the first casing 1A. As the second casing 1B moves to the enlarging position, the distance between the exhaust ports 45 and the exhaust fan 9 increases, so that the wind noise is restricted. As the second casing 1B moves to the reducing position, the exhaust ports 45 are concealed in the first casing 1A, so that the entry of the dust or the like into the projector 1 is prevented.