A projector including a projector body, which has a light modulating device that modulates light emitted from a light source according to input image information to thereby form an optical image and a projection optical device that projects the formed optical image in an enlarged manner; an image output device that outputs the image information to the projector body; a connection mechanism for connecting the projector body and the image output device with each other such that the projector body and the image output device can rotate relative to each other; a rotation operation detecting unit that detects a relative rotation operation of the projector body and the image output device; and a control unit that controls the projector body and the rotation operation detecting unit.