To provide a contact type atomic force microscope capable of rapidly obtaining a stable image of surface shape of a specimen in a state of an atmospheric pressure not in environmental control when the surface shape is measured by a contact mode having high sensitivity for irregularities.

A non-measuring region is provided outside a measuring region used to measure the surface shape, a modulation signal from a modulation signal oscillator 18 is given to a Z-scanner 6 to vibrate it in a Z-axis direction while a probe 2 is scanning the non-measuring region, thereby preventing an adsorption force acting between the specimen S and the probe 2.