Asking Google for different applications of electrolysis, interesting results can be noticed: electrolysis and hair removal - about 284 000 000 web pages, water electrolysis - about 7 440 000 web pages and industrial electrolysis - about 2 540 000 results. In this book three most important applications of technological electrolysis are discussed - water electrolysis (hydrogen production), industrial electrolysis and environmental electrolysis.