Abstract: This apparatus permits the non-destructive examination of entire surfaces for defects and contamination, and can detect microscopically small dot-shaped and linear defects and extremely fine macroscopic non-homogeneous areas. For this purpose, an adjustable lens system (5) is placed in the optical path between light source (2) and objective (9) which produces various intermediate images (31). A first cigar-shaped intermediate image is used for the first scan of the whole of the surface at a relatively large feed offset, and a second dot-shaped intermediate image is used for a second scan of partial areas of the surface at a small feed offset.A dark-field stop assembly (18) with an adjustable dark-field deflection system (8) is placed in the optical path between the lens system (5) and the objective (9), which projects the light beam (1) after deflection exactly centered at right angles through the objective (9) upon the surface of the object (10).