Abstract  The atomic force microscope (AFM), a member of the scanning probe family of microscopes, generates height maps of sample surfaces with subnanometer resolution. Importantly, AFM offers the opportunity to image samples with little or no treatment and under physiologically-relevant conditions, making it well-suited for investigating the structure of biological samples, including fixed or living cells and tissues. In addition to its high-resolution imaging capability, AFM used in force spectroscopy mode is a sensitive force measuring device, able to detect or exert forces ranging from the pico- to the nanonewton scale. Here we review a broad range of cell biological applications of AFM, including high resolution imaging of adherent cells, measuring cell adhesion down to the single-receptor level and characterizing the mechanical properties of cells. Furthermore, we present recent examples of how the combined use of AFM and advanced light microscopy techniques can provide complementary structural information.