Abstract: The invention concerns a device for filleting beheaded fish. Considering the deficiencies of known machines with regard to the aligning of the fish according to the position of the lower edge of their spinal column and with the purpose of removing these deficiencies at the same time using less expensive construction a transfer element is provided which can change its position directly due to the fish, which element is pivotal around the axis of a cutting tool opening the belly cavity and cutting free the belly spokes. First of all the cutting edges covered by the transfer element are set free, while the lower side of the spinal column is raised to the level of the bone guide following the cutting tool.