a substrate having a flow path of a single layer structure formed therein;

a fuel inlet portion for introducing fuel to the flow path of the substrate, the fuel inlet portion allowing the fuel to flow through a predetermined length of an inflow channel, thereby preheating the fuel;

an evaporator having a portion of the flow path, the evaporator disposed downstream of the fuel inlet portion to gasify liquid fuel;

a reformer having another portion of the flow path, the reformer disposed downstream of the evaporator to reform fuel into hydrogen gas via heat absorption reaction;

a CO remover having yet another portion of the flow path, the CO remover disposed downstream of the reformer to remove CO gas contained in the hydrogen gas via heat generation reaction; and

a cover for covering an upper part of the substrate to seal the flow path of the substrate from external environment, whereby the fuel flowing through the channel is heated,

wherein the evaporator, the reformer and the CO remover form the single layer structure,

wherein the inflow channel is configured in the form of a narrow flow path along a periphery of the substrate to surround the flow paths of the evaporator, the reformer and the CO remover,

wherein the flow path of the CO remover is formed in a zigzag shape by a plurality of partition walls each extended from a side of the substrate to another side of the substrate, and

wherein the inflow channel includes slits formed by the plurality of partition walls forming the flow path of the CO remover.