A scanning-mode microfocused total integrated scatter (TIS) instrument, the scanning scattering microscope (SSM), can produce two-dimensional images of very small surface and subsurface features and of variations in surface and buried interface roughness. In its present configuration, the lateral resolution is approximately 10 micrometer and the minimal detectable rms-roughness is 0.05 nm (with a bandwidth of 0.096 micrometer-1 to 1.56 micrometer-1). The performance of the SSM has been demonstrated using calibration gratings, Ge samples and ultra-smooth Si(100) and SiO2/Si(100) samples. Intercomparison has also been made with atomic force microscope (AFM) measurements. The results indicate that this scanned optical technique is a very sensitive, non-contact optical method for evaluating surface microroughness. Our measurements also indicate that in some cases, e.g. for ultrathin (less than 10 nm) SiO2 on Si, this optical method can be used to directly image microroughness of buried interfaces. Due to the small beam spot size, compared to a standard TIS, the SSM is applicable to the TIS measurements of rms roughness of small areas (of submillimeter diameter), e.g. craters made by secondary ion mass spectrometry (SIMS) techniques.