Disclosed is a plate type steam reformer comprising a plate type burner capable of heating a broad area of a reactor as a heat source, positioned on a bottom of the reformer; a reforming reactor requiring a relatively high temperature, positioned over the burner; a high temperature water gas shift reactor requiring a relatively moderate temperature, positioned over the reforming reactor; a low temperature water gas shift reactor requiring a relatively low temperature, positioned over the high temperature water gas shift reactor; and dividing plates positioned between the above three reactors and between the reforming reactor and the burner such that combustion exhaust gas produced in the burner supplies heat to the above reactors.