A method for manufacturing a separator assembly for a fuel cell, in which a channel through which a fluid flows is formed so as to be provided adjacent to a membrane electrode assembly, the method for manufacturing a separator assembly for a fuel cell comprising: a preparation step for preparing a first separator having an irregular cross-sectional shape, a second separator having an irregular cross-sectional shape, and an electroconductive elastic member having a contour smaller than a plan-view contour of the first separator and the second separator as viewed from a planar direction, the elastic member being arranged between the first separator and the second separator, and elastically deforming to maintain contact between convex portions of the first separator and convex portions of the second separator that face each other; a first placement step in which first positioning members provided on a placement surface are brought into contact with the elastic member such that the elastic member is positioned and placed on the placement surface; a second placement step in which second positioning members provided in a region of the placement surface that is further outward than a region in which the first positioning members are provided are brought into contact with the first separator such that the first separator is positioned in relation to the elastic member and placed so as to overlap the elastic member; and a joining step for joining together the elastic member and the first separator, which have been positioned and made to overlap, and in the second placement step, the first separator is made to overlap the elastic member while the first positioning members for positioning the elastic member are made to retract into the placement surface. a preparation step for preparing a first separator having an irregular cross-sectional shape, a second separator having an irregular cross-sectional shape, and an electroconductive elastic member having a contour smaller than a plan-view contour of the first separator and the second separator as viewed from a planar direction, the elastic member being arranged between the first separator and the second separator, and elastically deforming to maintain contact between convex portions of the first separator and convex portions of the second separator that face each other; a first placement step in which first positioning members provided on a placement surface are brought into contact with the elastic member such that the elastic member is positioned and placed on the placement surface; a second placement step in which second positioning members provided in a region of the placement surface that is further outward than a region in which the first positioning members are provided are brought into contact with the first separator such that the first separator is positioned in relation to the elastic member and placed so as to overlap the elastic member; and a joining step for joining together the elastic member and the first separator, which have been positioned and made to overlap, and in the second placement step, the first separator is made to overlap the elastic member while the first positioning members for positioning the elastic member are made to retract into the placement surface.