The invention relates to a method for manufacturing an assembly (1) for a fuel cell comprising at least two adjacent cell components, applied by means of the successive steps consisting of: a) solidifying by laser sintering a powder layer (Ci) deposited beforehand so that it forms a section of the assembly; and b) depositing a successive powder layer on the powder layer (Ci) deposited beforehand and solidified by laser sintering; the steps a) and b) being alternately repeated until the obtained stacked sections form together the assembly comprising at least two components. According to the invention, the method is applied so that at least one of the obtained sections (S1-Sp) has at least two areas with different porosities.