TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Reactor: In the reactor above, the metal film is formed by metalizing plating. In a state in which the post-heat-treatment metal film surface and the air electrode portion are connected through an electrically conductive adhesive paste, a second heat-treatment is performed to solidify the adhesive paste and thus the post-heat-treatment metal film surface and the air electrode portion are electrically connected. The negative pressure is adjusted to be from 10-5 to 10-1 Pa, in the first heat-treatment. The temperature is adjusted to be from 500 to 900 degrees C, in the first heat-treatment. Duration time of the first heat-treatment is from 10 minutes to 3 hours. The working temperature of the reactor is 500 to 1000 degrees C. The reaction member is a sheet body formed by stacking and firing a solid electrolyte layer as the electrolyte portion, a fuel electrode layer as the fuel electrode portion formed on the upper surface of the solid electrolyte layer, and an air electrode layer as the air electrode portion formed on the lower surface of the solid electrolyte layer; the sheet bodies and metallic separators supporting the sheet bodies are stacked in alternating layers; for each of the sheet bodies, a fuel channel, through which the fuel gas flows, is formed and defined in a space between an upper separator, which is the separator adjacent to the upper side of the sheet body, and the sheet body, as well as, an air channel, through which the oxygen-containing gas flows, is formed and defined in a space between a lower separator, which is the separator adjacent to the lower side of the sheet body, and the sheet body; for each of the sheet bodies, the electrically conductive member is confined in the air channel such that the electrically conductive member is electrically connected with both the lower separator and the air electrode layer of the sheet body; and for each of the electrically conductive members, the metal film is formed on the surface of at least the portion on the electrically conductive member, which is electrically connected with the air electrode layer, and the first heat-treatment is performed on the electrically conductive member after the formation of the metal film, and the electrically conductive member and the air electrode layer are electrically connected by electrically connecting the air electrode layer and the post-heat-treatment metal film surface. Electrically conductive member is made of stainless steel. The electrically conductive member is made of stainless steel, and the metal film is made of silver (Ag). The proportion of the chromium concentration in the layer containing Cr2O3 to the chromium concentration in the electrically conductive member is from 0.3 to 1.5. Preferred Method: During the metal film forming step, the metal film is formed by metalizing plating. Electrically connecting step includes in a state in which the post-heat-treatment metal film surface and the air electrode portion are connected through an electrically conductive adhesive paste, performing a second heat-treatment to solidify the adhesive paste and thus electrically connecting the post-heat-treatment metal film surface and the air electrode portion.