A method for the degradation of industrial wastewater, which provides, in a first step a., sending a predefined quantity of wastewater to an apparatus (1) provided with a respective containment tank (2); then, in a second step b., the method consists in administering to the predefined quantity of wastewater a first additive for adjusting the pH value, in order to bring it to a first predefined value. Upon reaching the first predefined pH value, in a step c. hydrogen peroxide and an iron salt are added to the predefined quantity of wastewater, in order to induce the forming of hydroxyl radicals, suitable for the advanced oxidation of substances of various types present in the predefined quantity of wastewater, for an at least partial first degradation thereof. Then, in a step d., the method according to the invention provides for adding to the predefined quantity of wastewater a second additive for adjusting the pH value, in order to bring it to a second predefined value, adapted to facilitate the spontaneous decomposition of the residual hydrogen peroxide and the precipitation of iron hydroxides, for a second degradation of the remaining substances of various types present in the predefined quantity of wastewater; finally, in a step e., the containment tank (2) is evacuated, for the final disposal of the predefined quantity of wastewater, substantially degraded.