there is disclosed a process for producing a hydrogen - containing gas , which comprises reacting methanol , steam and oxygen in the presence of a catalyst comprising palladium , zinc and at least one metal selected from the group consisting of chromium , gallium , copper , indium , bismuth and platinum . that is to say , the process include the following four aspects : a process which comprises reacting methanol , steam and oxygen in the presence of a catalyst comprising palladium , zinc , and either or both of chromium and gallium ; a process which comprises reacting methanol , steam and oxygen in the presence of a catalyst comprising palladium , zinc , copper and chromium ; a process which comprises reacting methanol , steam and oxygen in the presence of a catalyst comprising palladium and zinc , or chromium added thereto optionally , and either or both of indium and bismuth ; and a process which comprises reacting methanol , steam and oxygen in the presence of a catalyst comprising zinc oxide , palladium and platinum . the use of the above steam - reforming catalyst having a high activity , high selectivity and sufficient durability makes it possible to produce a hydrogen - containing gas which is composed principally of hydrogen and minimized in co concentration in an industrially advantageous manner through an auto thermal reformer where methanol , steam and oxygen are reacted with one another .