Electromechanical devices such as relays, switches, connectors and printed wiring boards have shown quick growth along with remarkable progress of electronic products in a recent few decades. For the present, outstanding tasks common to these devices are further downsizing, higher density and broading of bandwidth, on the assumption of keeping high performance and high reliability. These tasks are realized by part production improvement for higher precision and automatic assemblies, development of constituent materials and development of breakthrough structural technologies such as a surface mount technology and an active assembly ferrule technology in optical connectors and so on. In this paper, the technical trends as well as the motive technologies are overviewed for each device.