NOVELTY - The reaction apparatus useful as a micro reactor in a reforming fuel cell, comprises a reaction container having a hollow box member, a partition plate, which is disposed to partition a space inside the box member and to form a reaction passage for flowing the reactant, a parallel partition plate, a base plate, and a heat-insulating container to house the reaction container. The box member has a first plate in which a supplying passage of the reactant is formed, a second plate arranged opposite to the first plate, and a third plate provided with edges of the first and second plates.    USE - Useful as a micro reactor in a reforming fuel cell.    ADVANTAGE - The reaction apparatus reduces heat losses thus avoids deforming of outer wall surfaces of the reaction container, and prevents breaking of the reaction container during reduction of wall thickness while maintaining the strength of the reaction container.    DETAILED DESCRIPTION - The reaction apparatus useful as a micro reactor in a reforming fuel cell, comprises a reaction container having a hollow box member, a partition plate, which is disposed to partition a space inside the box member and to form a reaction passage for flowing the reactants, a parallel partition plate, a base plate, and a heat-insulating container to house the reaction container. The box member has a first plate in which a supplying passage of the reactant is formed, a second plate arranged opposite to the first plate, and a third plate provided with edges of the first and second plates. The parallel partition plate is disposed parallel to the second plate in the reaction container and partitions the space inside the box member. The base plate is joined to the first plate and reinforces the first plate. The second plate has lower rigidity than the first plate. The second plate and the partition plate are joined to each other by welding or brazing. The second plate, the third plate and the partition plate are formed of a metal material. The partition plate has a diaphragm portion and a joint portion that are provided in a perpendicular direction to the second plate. The joint portion and the second plate are joined to each other. A first- and second through area that form the reaction passage are provided in the partition plate. The partition plate has a rectangular or triangular wave shape. A wave height direction of the rectangular or triangular wave is set parallel to the second plate. The heat-insulating container has an inner space of which a pressure is set lower than an atmospheric pressure. The reactant reaction takes place in a first- and second reaction portion of the reaction container at high- and low temperature respectively. A coupling portion transfers the reactant and a product between the first reaction portion and the second reaction portion. The first reaction portion is a reformer, which causes a reforming reaction of the first reactant to form a first product containing hydrogen and carbon monoxide, and the second reaction portion is a carbon monoxide remover to remove carbon monoxide contained in the first product.    DESCRIPTION OF DRAWING(S) - The diagram shows a micro reactor module as a reaction apparatus:    Introduction pipe; (622)    Insulating plate; (640)    Base plate; (642)    Base portion; (662)    Plate member. (690)