Hydrogen separation is one of the larger applications of metallic membranes. Mostly, palladium (Pd)-based membranes have been developed and used for this application because of their high flux and high permselectivity. This chapter will discuss in more detail the production and use of supported and unsupported membranes for hydrogen separation. Particularly, the supported thin film Pd membranes are discussed in more detail as these are the closest to the market. Production methods are discussed along with the pros and cons of these types of membranes.