Patent ID: 7086745

Claim:
An optical component casing with an illumination optical axis of a light beam irradiated by a light source being set therein, in which a plurality of optical components are housed and arranged at predetermined positions on the illumination optical axis, the casing comprising: a lower casing in which the plurality of optical components are housed; a lid-shaped upper casing that closes the lower casing; an optical component holding frame that holds at least one of the plurality of optical components and arranges the optical component at a predetermined position inside the lower casing, wherein an optical component holding frame supporting surface, which is a curved surface being circular around the illumination optical axis of the light beam as the center to rotatably support the optical component holding frame, is formed on an upper side of the upper casing, the optical component holding frame includes a first holding frame for holding one of the plurality of optical components and a second holding frame for holding the other optical component arranged closely to the optical component held by the first holding frame, and the one of the first and second holding frames slides on the optical component holding frame supporting surface of the upper casing, is formed as a curved surface being circular around the illumination optical axis of the light beam as the center, and has a rotation guiding surface that rotatably supports the other one holding frame.