A microcomputer‐controlled gravimetric adsorption apparatus was designed and constructed. Components and software of the system are described. A microcomputer is used to control the experiment and to acquire data. The system is capable of conducting a complete adsorption–desorption run for various adsorbate/adsorbent systems quite accurately and efficiently. Results of the sorption of water and nitrogen on oxide and hydroxide powders are presented to demonstrate the performance of the apparatus.