This invention consists of a device for the treatment and elimination of bacteria in combustible hydrocarbons, whose function is to ensure the purity of said fuels. The elimination of bacteria takes place catalytically thanks to the alloy of which its inner part is composed and the interaction with the casing containing it. This device has the advantage of having a more intense effect of eliminating microbiological contamination than other technologies. It is installed inside the fuel tanks. Its design allows that its presence in the tank does not cause damage to the components that may be inside it.