A method for the manufacture of an integrally reinforced lightweight structure with a fibre-reinforced plastic, in particular of a fuselage barrel or a shell component of an aircraft, by means of a moulding tool, wherein the lightweight structure has a multiplicity of stiffening ribs crossing one another at node points (22, 24, 70, 78, 90-96), wherein a skin is attached to the stiffening ribs and the moulding tool has a multiplicity of channel-type depressions for purposes of creating the stiffening ribs, comprising the following steps: a) laying down in at least some regions of at least one intermediate layer (54, 98, 100) and at least one reinforcement layer into the depressions, wherein the at least one reinforcement layer is severed before at least one node point (22, 24, 70, 78, 90 - 96) and behind the node point (22, 24, 70, 78, 90 - 96) in the region of the groove is restored, or that at least one recess (114, 116) is introduced into the at least one intermediate layer (54, 98, 100) in the region of the at least one node point (22, 24, 70, 78, 90-96) in at least some regions. b) repetition of step a) until the depressions are at least partially filled. with intermediate layers (54, 98, 100) and reinforcement layers for purposes of forming the stiffening ribs with integral connecting feet (60, 62, 106-112), c) population of the moulding tool, in particular with intermediate layers (54, 98, 100) and/or reinforcement layers, for purposes of manufacturing the skin, and d) curing and/or solidification of the intermediate layers (54, 98, 100) and reinforcement layers, wherein the at least one depression is formed with a groove with two side walls (40, 42) and a groove edge zone (44, 46) is attached in at least some sections to at least one side wall (40, 42), wherein the grooves have an approximately trapezoidal cross-sectional geometry while the groove edge zones formed in mirror-images on the two sides of the grooves have an approximately triangular or wedge-shaped cross-sectional geometry and groove edge zones undergo a smooth, i.e. stepless, transition into a surface of the moulding tool, wherein the reinforcement layers are laid down in the groove, and the intermediate layers (54, 98, 100) are laid down in the groove and in the at least one adjacent groove edge zone (44, 46), wherein the stiffening ribs are formed with a multiplicitv of reinforcement layers and intermediate layers (54, 98, 100) laid down one upon another. a) laying down in at least some regions of at least one intermediate layer (54, 98, 100) and at least one reinforcement layer into the depressions, wherein the at least one reinforcement layer is severed before at least one node point (22, 24, 70, 78, 90 - 96) and behind the node point (22, 24, 70, 78, 90 - 96) in the region of the groove is restored, or that at least one recess (114, 116) is introduced into the at least one intermediate layer (54, 98, 100) in the region of the at least one node point (22, 24, 70, 78, 90-96) in at least some regions. b) repetition of step a) until the depressions are at least partially filled. with intermediate layers (54, 98, 100) and reinforcement layers for purposes of forming the stiffening ribs with integral connecting feet (60, 62, 106-112), c) population of the moulding tool, in particular with intermediate layers (54, 98, 100) and/or reinforcement layers, for purposes of manufacturing the skin, and d) curing and/or solidification of the intermediate layers (54, 98, 100) and reinforcement layers, wherein the at least one depression is formed with a groove with two side walls (40, 42) and a groove edge zone (44, 46) is attached in at least some sections to at least one side wall (40, 42), wherein the grooves have an approximately trapezoidal cross-sectional geometry while the groove edge zones formed in mirror-images on the two sides of the grooves have an approximately triangular or wedge-shaped cross-sectional geometry and groove edge zones undergo a smooth, i.e. stepless, transition into a surface of the moulding tool, wherein the reinforcement layers are laid down in the groove, and the intermediate layers (54, 98, 100) are laid down in the groove and in the at least one adjacent groove edge zone (44, 46), wherein the stiffening ribs are formed with a multiplicitv of reinforcement layers and intermediate layers (54, 98, 100) laid down one upon another.