Portable device for biological wastes disinfection by sequential application of different disinfecting compounds comprising an upper opening, a cover preventing residual gases of the disinfection from being released and at least one side wall comprising: a programmable metering unit, at least two disinfecting compound dispensers, a residual liquid ejecting element, at least one projection inside thereof and handles at the side wall. On the other hand, a method for disinfection of biological wastes by means of the device described above, based on the sequential application of different compounds by at least a metering unit being installed in the device that allows determining the time for the disinfection cycle and the appropriate dose of the compound, and warning of the end of the process so as to eliminate the residual liquid by means of the ejecting element of the device.