We produced the Ni-Nb-Zr-Co amorphous membranes by single-roller melt-spinning technique and measured the hydrogen permeation behavior of them. The palladium thin films were deposited on both sides of membranes as catalysts for hydrogen dissociation. The hydrogen permeability of the Ni-Nb-Zr-Co amorphous alloys increased with increasing test temperature and was much larger than that of the conventional Pd-Ag alloy. The durability of the alloys during service was also examined at 573 K and 673 K. As a result, it was found that the permeability decreased significantly with time at 673 K. However, the permeability did not almost decrease at 5,73 K even after 100 h. Furthermore, we developed the manufacturing technique to fabricate the 100 mm wide hydrogen separating amorphous membranes. (c) 2006 Elsevier B.V. All rights reserved.