An assembly jig for a cellular structure made from strips of material placed adjacent to each other and joined together so as to form first and second cells, opening on the first and second faces of the cellular structure, respectively. This assembly jig includes a housing delimited by a base and first and second side faces, configured for housing the strips of material of a cellular structure to be formed, superimposed on each other, a plurality of pins configured to be positioned between the superimposed strips of material in the first and/or second cells. An assembly device comprising the jig, and a method for manufacturing a cellular structure using the jig are also provided.