Clean steel encompasses a multitude of concepts that are based on fulfilling customer requests. Clean steel can be produced in many ways depending on the existing equipment and detailed customer demands. A common feature of all clean steel production is tight process control along with continuous monitoring. Quality assurance is essential and it still requires many improvements. There are no specific obstacles to clean steelmaking, as the industrial processes are available, sufficiently understood and controlled. The major issues to be addressed remain disturbances that occur in industrial reality. This asks for continuous improvements in processes and equipment and for further development of quality assurance systems to achieve full control of any possible detrimental effect.