Method for preparing a chitosan-based porous layer The present invention relates to a method or preparing a chitosan-based, neutralized compressed porous layer, comprising the following steps: —a) a chitosan solution is prepared, —b) said solution is poured into a mould in order to form a layer, —c) the layer obtained in b) is lyophilized so as to obtain a porous layer, —d) said porous layer obtained in c) is compressed, —e) the compressed porous layer obtained in d) is neutralized by means of an NH4OH solution. It also relates to an implant comprising a layer obtained according to such a method.