The scanning tunneling microscope (STM) is a powerful instrument which gives information on topography, chemical composition and electronic properties of metal and semiconductor surfaces down to the atomic scale. This microscope has been significantly enhanced by an automated control and data-acquisition system. Microprocessor-controlled intelligent instruments grouped around an IBM PC/AT control computer drive the STM and acquire experimental data. Both the hardware and the software are built in a modular manner. Therefore, the control and acquisition system can be tailored to the size, complexity and type of application of the STM instrument. We shall discuss the concept of the automated microscope and explain the functions of the instruments and the software. © 1987.