In the chemical industry (less so in the pharmaceutical industry), membrane technology is still at an early stage of acceptance. However, in this field too, it is gaining increasing importance as an innovative, reliable and, first and foremost, cost-effective alternative to conventional processes. This trend is evidenced by a variety of new plants which have been installed in recent years, and also by the rapidly growing interest in this technology shown by production and design departments. This article gives an overview of the industrial importance of membrane processes in chemical and pharmaceutical production and also presents some typical examples of applications in this field by describing plants which have already been installed and are now in production.