Process for producing a demountable structure including: - forming a first bond by molecular bonding one side of a first wafer to one side of a second wafer, at least one of the sides including a silicon-oxide layer (12, 13); and - before the first bond is formed, a step of processing at least one of these sides, said processing step being suitable for bringing the mechanical strength of the interface of the first bond between the two wafers to a controlled level; - the formation of this first bond is followed by a step of demounting the entirety of the interface of the first bond; - between the formation of the first bond of the structure and this demounting step a step of completely or partially producing microelectronic, optoelectronic, mechanical, piezoelectric, superconductor or magnetic components is carried out and a second bond is formed by molecular bonding, the structure being bonded to a substrate (16, 16') during said bonding, said controlled level of mechanical strength therefore being compatible with said step of completely or partially producing components on at least one of the two wafers, and also compatible with said subsequent step of demounting the structure, and lower than the mechanical strength of the interface of the second bond; and - the structure is demounted at the interface of the first bond: • by submerging the stack of the demountable structure and of the substrate bonded to this demountable structure in an HF-acid bath in order to attack less area at the interface of the second bond than at the interface of the first bond, then • by implementing a separation of mechanical character at the interface of the first bond. - forming a first bond by molecular bonding one side of a first wafer to one side of a second wafer, at least one of the sides including a silicon-oxide layer (12, 13); and - before the first bond is formed, a step of processing at least one of these sides, said processing step being suitable for bringing the mechanical strength of the interface of the first bond between the two wafers to a controlled level; - the formation of this first bond is followed by a step of demounting the entirety of the interface of the first bond; - between the formation of the first bond of the structure and this demounting step a step of completely or partially producing microelectronic, optoelectronic, mechanical, piezoelectric, superconductor or magnetic components is carried out and a second bond is formed by molecular bonding, the structure being bonded to a substrate (16, 16') during said bonding, said controlled level of mechanical strength therefore being compatible with said step of completely or partially producing components on at least one of the two wafers, and also compatible with said subsequent step of demounting the structure, and lower than the mechanical strength of the interface of the second bond; and - the structure is demounted at the interface of the first bond: • by submerging the stack of the demountable structure and of the substrate bonded to this demountable structure in an HF-acid bath in order to attack less area at the interface of the second bond than at the interface of the first bond, then • by implementing a separation of mechanical character at the interface of the first bond. • by submerging the stack of the demountable structure and of the substrate bonded to this demountable structure in an HF-acid bath in order to attack less area at the interface of the second bond than at the interface of the first bond, then • by implementing a separation of mechanical character at the interface of the first bond.