A method for manufacturing a fuel cell stack body includes a step of forming a plurality of line-shaped separator cross-sectional patterns. In the patterns, a first direction along the build surface is the stacking direction, and a second direction orthogonal to the first direction is the planar direction of the separators. The patterns extend in the second direction and meander so as to have convexities and concavities in the first direction. The manufacturing method further includes a step of forming the electrolyte membrane cross-sectional pattern and a step of forming the electrode cross-sectional patterns. These steps are repeated to perform stacking in a direction perpendicular to the build surface.