PURPOSE: To selectively project and expose the first and second patterns formed on the first object onto the second object by a device wherein light-shading plates are moved independently from one another and the shape of an opening through which a light flux coming from a light source passes can be changed.

CONSTITUTION: The plane of an opening 35 is situated on the same plane as a light-shading surface A at a light-shading device 18. Regarding the moving direction of four light-shading plates 34 the first and second light-shading plates move in the identical direction, while the third and fourth light-shading plates move in the identical direction. The moving direction of the first and second plates is not identical in relation to that of the third and fourth plates. Four motors 31 are installed on each plate for moving each light-shading plate 34 independently from one another. Through this arrangement, the first and second patterns formed on the first object can be projected and exposed selectively onto the second object. When, for example, the second object like a wafer is exposed through the first object like a reticle, plural different patterns can be projected and exposed efficiently onto the second object.