For quantitative depth profile analysis of hard and wear resistant coatings (general composition, metal-C:N:O:H:Ar) by secondary ion mass spectrometry (SIMS) the use of Cs' primary ions in conjunction with the detection of MCs+ (M: element of interest) molecular ions is proposed. As compared with Rutherford backscatterring spectrometry (RBS)/elastic recoil detection (ERD), the accuracy of MCs+-SIMS is about +/- 10%, irrespective of oxygen concentrations up to 20 at.%. A depth resolution of Deltaz similar to 30 nm at a depth of z = 2.5 mum is demonstrated on curved (radius 2 mm) surfaces of polished (R-a similar to 0.005 mum) steel. On rough surfaces (R-a > 0.1 mum) the depth resolution significantly degrades (Deltaz = 120 nm at z = 2.5 pm) due to effects of shadowing and redeposition. This limits detailed and quantitative studies of interlayers and interfaces. Examples are given for local depth profile analysis on technical components under difficult conditions of surface geometry and topography.