A method for preparing peroxide, including a step of treating, in a reaction medium, a component having at least one tertiary alcohol grouping with a compound having at least one tertiary hydroperoxide function in the presence of a catalyst, said method being characterised in that the catalyst includes a sulphonic acid and a inorganic acid, the molar ratio between the sulphonic acid and the aforementioned component including at least one tertiary alcohol grouping ranges from 0.05 to 0.8, and the molar ratio between the inorganic acid and the aforementioned component including at least one tertiary alcohol grouping ranges from 0.05 to 0.8. Also, to the peroxide resulting directly from said preparation method.