A method for manufacturing a multispectral filter for electromagnetic radiation, said filter including at least two colour filters (Fi), each filter including a first reflective layer, a second reflective layer, and a layer of dielectric material of Fabry-Perot cavity between the first reflective layer and the second reflective layer, the thickness of the dielectric layer of both colour filters being different and each of both filters (Fi) facing a photoelectric transducer, said method including the following steps of: - Depositing a resin layer on a substrate, called the handle substrate; - Three-dimensionally structuring the resin layer by lithography so as to obtain at least two resin patterns of different heights, at least one of the patterns having a maximum reference height (Hmax), the height being measured perpendicularly to the plane of the substrate; - Depositing a layer made of the dielectric material intended to form the dielectric patterns of the Fabry-Perot cavities, said layer of dielectric material covering the entire resin patterns by having an upper surface, each point of which is located at a height relative to the handle substrate greater than the maximum reference height (Hmax); - Planarising by removal of the dielectric material with a selective stop at the top of the highest resin pattern; - Transferring (106, 107) the planarised face of the handle substrate to the upper face of a substrate, called the carrier substrate, including at least two photoelectric transducers, each of said patterns facing a photoelectric transducer, a reflective layer intended to form the first reflective layer of both colour filters being positioned at the transfer interface between the handle substrate and the carrier substrate; - Removing the handle substrate; - Removing the resin so as to release at least two dielectric patterns of Fabry-Perot cavities of different thicknesses on the surface; - Depositing a reflective layer onto the at least two dielectric patterns of Fabry-Perot cavity, forming the second reflective layer of both colour filters. - Depositing a resin layer on a substrate, called the handle substrate; - Three-dimensionally structuring the resin layer by lithography so as to obtain at least two resin patterns of different heights, at least one of the patterns having a maximum reference height (Hmax), the height being measured perpendicularly to the plane of the substrate; - Depositing a layer made of the dielectric material intended to form the dielectric patterns of the Fabry-Perot cavities, said layer of dielectric material covering the entire resin patterns by having an upper surface, each point of which is located at a height relative to the handle substrate greater than the maximum reference height (Hmax); - Planarising by removal of the dielectric material with a selective stop at the top of the highest resin pattern; - Transferring (106, 107) the planarised face of the handle substrate to the upper face of a substrate, called the carrier substrate, including at least two photoelectric transducers, each of said patterns facing a photoelectric transducer, a reflective layer intended to form the first reflective layer of both colour filters being positioned at the transfer interface between the handle substrate and the carrier substrate; - Removing the handle substrate; - Removing the resin so as to release at least two dielectric patterns of Fabry-Perot cavities of different thicknesses on the surface; - Depositing a reflective layer onto the at least two dielectric patterns of Fabry-Perot cavity, forming the second reflective layer of both colour filters.