The first electron bombarded semiconductor (EBS) devices have recently appeared on the market. These devices have already demonstrated that EBS has considerable promise as an important new electron device for power amplification and control. EBS devices are described with particular emphasis on power devices. The basic EBS principle, some of the analysis used in device design, general considerations in designing the various elements of the device, overall device design, semiconductor processing, and reliability considerations are discussed. Predictions of general directions for future work are made. Some historical information is also presented as well as a brief comparison with other competing power devices.