Abstract: In a method for producing a porous ceramic compound, a green layer is disposed onto a previously sintered ceramic substrate and is sintered with the previously sintered substrate at temperatures between 500° C. and 1300° C., wherein the green layer comprises exclusively ceramic particles having a particle size of x?100 nm and the sintered green layer being a functional layer has a layer thickness of s?2.5 ?m. The functional layer produced in this method is flawless and fine-pored and therefore particularly suited for filtration processes.