The invention relates to a method of manufacturing a lamination stack used in a rotating electrical machine. The method includes providing naked sheets made of ferritic material; preparing both sides of each sheet so as to obtain a determined surface roughness; coating at least one side of each sheet with an chemically protective electrically insulating material; stacking the coated sheets; compressing the stack obtained; heating the compressed stack at a temperature above the melting temperature of the insulating material; and cooling down the compressed stack so as to form an integral lamination stack consisting of alternating sheets of ferritic material and layers of insulating material. The invention also relates to an electrical machine comprising such a lamination stack.