A process for producing a flaked cellulose-based thermal- and/or acoustic-insulating material includes preparing a cellulose-based pulp and providing a web of paper having a given thickness, starting from the pulp. A coating having a mixture containing a first substance having a flame-retardant function and a second substance having an anti-mould function is applied on the web. The coated web is subjected to a milling operation so as to provide flakes of flaked insulating material.