A new scanning tunneling microscope/scanning electron microscope (STM/SEM) combined system has been developed based on an ultrasmall size STM that can be placed and removed from a SEM commercial chamber without breaking the vacuum. The STM device allows three-dimensional coarse positioning of the tip by means of inertial drive mechanisms. The total XY movement is 1 mm2 with a resolution of 50 nm. In that way STM images can be obtained on any preselected spot of the sample under simultaneous tip and sample SEM inspection. The stability of the microscope is high enough as to obtain atomic resolution on highly oriented pyrolithic graphite.