We have implemented an apertureless Scanning Near-Field Optical Microscope (SNOM) setup on a commercial Atomic Force Microscope (AFM), using a suitable optical apparatus and preserving AFM performances. This approach is promising for extending SNOM analysis to delicate samples, such as liquid or polymer films. Preliminary measurements on glass-metal nanometric steps show a lateral resolution better than 10 nm both in topography and in optical signal.