According to example embodiments, an atomic force microscope includes a probe tip, a cantilever including the probe tip, a displacement measurement device, and a movement device. A vibrating displacement of the cantilever changes according to a force between atoms of the probe tip and atoms of a surface of a sample. The displacement measurement device is configured to irradiate a beam emitted from a light source on the cantilever and to measure a displacement of the cantilever based on the beam reflected from the cantilever. The movement device is configured to move the cantilever and the displacement measurement device simultaneously when the sample is scanned.