This talk mainly aims to provide a general review of working principle and data analysis of atomic force microscopy (AFM). It includes not only AFM but also the basic ideas of magnetic force microscopy (MFM) and piezoelectric force microscopy (PFM). Since its invention (1986), AFM has played a crucial role in nano-scale science and technology. AFM is an amazing technique that allies a versatile methodology to image nano-scale phenomena in a variety of research fields including physics, chemistry, biology and engineering. It is a microscopic technique using attractive and repulsive forces between a few atoms attached at the tip on a cantilever and a sample.