Method for neutralizing formol, especially suitable for neutralizing formol used in centers for analyzing biological tissues, characterized in that it comprises the operations of:a) supplying and storing quantities of formol to be neutralized associated with various uses or analyses in at least one reaction vessel (3, 4)；b) stopping the supply of formol to be neutralized when a maximum fill level of the formol content inside the reaction vessel (3, 4) has been reached in order to initiate the neutralization process；c) supplying an ozone current inside the reaction vessel (3, 4) to produce a mixture with the formol content during a pre-established time to generate the neutralization process of the formol；d) stopping the supply of the ozone current when the neutralization process of the formol has finished； ande) draining the content of neutralized formol from the reaction vessel (3, 4) for its disposal.
