A steam reforming apparatus (21) is configured to be placed in an industrial furnace (100) sintering an article to be sintered with a heat generated by fusing a fuel and to use a fed hydrocarbon and fed steam as raw materials. The apparatus (21) includes a low-temperature reforming section (23) and a high-temperature reforming section (22). The low-temperature reforming section (23) includes a metal tubular reactor (25) or a ceramic tubular reactor each housing a reforming catalyst for accelerating a steam reforming reaction, and the high-temperature reforming section (22) includes a ceramic tubular reactor (24) to cause a steam reforming reaction inside thereof. There is provided a steam reforming apparatus capable of recovering waste heat by using part of the combustion heat (waste heat) of the industrial furnace efficiently in accordance with the temperature range thereof.