Abstract: A projection exposure apparatus for projecting a pattern image of an illuminated mask onto a substrate. The optical path can be divided into a plurality of hermetic blocks each having an inert gas sealed therein by a plurality of partition devices. According a one aspect of the invention, a hermetic sealing member is disposed in the space between the substrate-side of the projection optical system and the substrate for replacing the atmosphere existing in the optical path of the illuminating light in that space by a substance other than oxygen. According to another aspect of the invention, a plurality of independent chambers are formed in a frame. Lids, piping, and valves in the chambers are opened or closed in response to the value detected by oxygen density sensors.

Abstract: A light source device houses a lamp such as a mercury discharge tube for generating a high temperature heat, and a reflective optical member such as an elliptic, mirror surrounding the lamp, in a lamp case. When the lamp is forcibly cooled by air, a device for substantially uniformly heating or heat-insulating a reflection surface of the reflective optical member is provided to prevent overcooling of the reflective optical member.

Abstract: An illumination optical apparatus includes secondary light source forming means for forming a plurality of light source images from collimated light beams emitted from a light source, tertiary light source forming means arranged midway along an optical path from the secondary light source forming means, and a condenser lens arranged midway along an optical path from the tertiary light source forming means. The secondary light source forming means includes an optical integrator having entrance and exit surface. A plurality lens surface having a larger focal length than a distance between the entrance and exit surfaces are formed on the entrance sarfaces. Thus, a plurality of secondary light source images are formed by the secondary light source forming means in a space behind the exit surface of the optical integrator.

Abstract: A method and apparatus for inspecting masks and reticles by simplifying rotational alignment thereof so as to shorten alignment time is proposed wherein a rotational angle representing a rotational error between a reference substrate and a substrate to be inspected is measured in advance, the substrate to be inspected being provided with the same circuit patterns as those of the reference substrate in one-to-one correspondence, a position of a stage having these substrates thereon is automatically measured, and a measurement error caused by the rotational error can be automatically corrected, thereby providing accurate measured values.