By applying a direct current to a proton-conducting ceramic membrane, hydrogen can be electrochemically transported across the membrane. This is a kind of electrochemical hydrogen pump. This pump may be applied to devices for the separation, the removal or the supply of hydrogen. In this paper, the working principles and advantages of the hydrogen pump and its derivatives are described. Some experimental results obtained in the author's laboratory using perovskite-type oxide proton-conducting ceramics as a solid electrolyte are also introduced.