A scanning probe microscope that facilitates the optical axis adjustment operation at the time of initial cantilever installation and at the time of cantilever replacement. During the optical axis adjustment operation, markers are displayed on the video camera image at the cantilever and laser light center of luminance locations, and the markers, which follow the movement of the laser light location, are visually monitored and superposed. Furthermore, optical axis adjustment for a new cantilever is performed using marker location coordinate data stored after the initial optical axis adjustment. Moreover, by setting the target location coordinates, the direction of movement of laser light and the distance to the target location can be ascertained numerically.