NOVELTY - Catalytic partial oxidation reforming reactor comprises a catalyst accommodating chamber (20) for accommodating a modified catalyst layer and passing fuel, preferably propane, and an extension part (30a) located on both sides of the catalyst accommodating chamber. The extension part is provided in smaller diameter than catalyst accommodating chamber. The extension part is formed of stainless steel. The extension part is formed of stainless steel. The catalyst accommodating chamber is spatially segmented in first (20a), second (20b) and third zones (20c) based on introducing sequence of fuel.    USE - The reactor is useful in portable solid oxide fuel cell (claimed).    ADVANTAGE - The reactor improves stability of catalyst by forming small size. The portable solid oxide fuel cell is smaller, and easily controls high hydrogen production and heat of reactor, and quickly processes reaction in normal condition.    DETAILED DESCRIPTION - Catalytic partial oxidation reforming reactor comprises a catalyst accommodating chamber (20) for accommodating a modified catalyst layer and passing fuel, preferably propane, and an extension part (30a) located on both sides of the catalyst accommodating chamber. The extension part is provided in smaller diameter than the catalyst accommodating chamber. The catalyst accommodating chamber is formed of carbon steel pipe. The extension part is formed of stainless steel. The catalyst accommodating chamber is spatially segmented in first (20a), second (20b) and third zones (20c) based on introducing sequence of fuel. The first zone is a fuel heating zone located in inside and shearing section of the catalyst accommodating chamber. An INDEPENDENT CLAIM is also included for a portable solid-oxide fuel cell for: supplying power in each component of an internal battery when operation is initiated, performing initialization and checking, and starting air supply into the reforming reactor by starting air blower; heating the reforming reactor by supplying power on electrically heated catalyst, and then supplying fuel when the temperature of the reforming catalyst reaches the appropriate temperature; heating the supplied fuel using a modified gas rear burner by combustion reaction and operating the rear end of the combustor; heating a stack supplied on stack of cathode when the preheated air reach to appropriate temperature through the heat exchanger; and supplying modified stack gases to an anode when the temperature of the stack reaches the appropriate temperature.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic representation of the catalytic partial oxidation reforming reactor.    Reforming reactor (10)    Catalyst accommodating chamber (20)    First zone (20a)    Second zone (20b)    Third zone (20c)    Extension part (30a)