Abstract: The present invention relates to a method for manufacturing an internal shell of a composite type IV reservoir delimiting an internal cavity intended to accommodate a pressurized fluid and comprising at least one metal baseplate allowing connection between said internal cavity and the outside of the internal shell, said baseplate or baseplates being secured to the internal shell, said method comprising the following steps: a) a step of applying at least one adhesive layer of a first polymer to the part or parts of the metal baseplate or baseplates intended to be in direct contact with the material of which the internal shell is made; b) a step of incorporating said baseplate or baseplates thus coated into a mould the internal cavity of which is of a shape that corresponds to the shape of the internal shell that is to be obtained; c) a step of forming, on the internal wall of the mould and on the part or parts of the baseplate or baseplates intended to be in contact with the material of which the internal s