NOVELTY - Manufacture of microreformer involves providing two substrates, each having a grooved path on one side and a catalyst layer formed in inner surface of grooved path; and bonding the two substrates in such way that the grooved paths are overlapped on each other to form a microchannel, a reforming section (10) adjacent to a fuel inlet, a carbon monoxide (CO) removing section (30) downstream of fuel inlet, and a hydrogen outlet downstream of CO removing section.    USE - Method for manufacturing microreformer for producing hydrogen gas from liquid fuel.    ADVANTAGE - The grooved paths are formed on both second substrates and overlapped on each other to form the microchannel, thus increasing the areas of microchannel and catalyst layer, and hydrogen emission amount per time to yield excellent reforming effect. The heating unit enhances heat efficiency, thus allowing the reformer to operate with low power. The first and second substrates can be machined via semiconductor process, e.g. microelectromechanical systems (MEMS), allowing mass production at low cost. The first substrate can be made of PDMS which enhances durability and thermal stability while simplifying manufacturing process at low cost. The reforming section and CO removing section can be disposed alongside while the output density of hydrogen gas can be increased.    DETAILED DESCRIPTION - Manufacture of microreformer involves:    (A) providing a first substrate (40) having a first grooved path (42) on one side and a catalyst layer formed in inner surface of first grooved path;    (B) providing a second substrate having a second grooved path (62) and a catalyst layer corresponding to the first grooved path and catalyst layer, and a heating unit (66); and    (C) bonding the first and second substrates in such way that the first and second grooved paths are overlapped on each other to form a microchannel, a reforming section adjacent to a fuel inlet (46), a CO removing section downstream of fuel inlet, and a hydrogen outlet (48) downstream of CO removing section.    DESCRIPTION OF DRAWING(S) - The drawing is an exploded perspective view of a microreformer.    Reforming section (10)    CO removing section (30)    First substrate (40)    First grooved path (42)    Fuel inlet (46)    Hydrogen outlet (48)    Second grooved path (62)    Heating unit (66)    Power source pads (66a)