Powder enamel applicator device for the decoration of ceramic tiles or slabs, with said powder enamel designed to reproduce a predetermined design or decoration, a variable quantity of the same enamel in powder being destined to be deposited at selected portions of the surface of said ceramic tile or plate, with the latter moved horizontally along a conveyor line below said applicator device, wherein it includes: - dispensing means, provided with a tray for containing said powder enamel, in said tray being provided at least one lower blade opening, extended transversely to the aforementioned tile or slab, for gravity release of the aforementioned powder enamel; - a metering unit, arranged below said dispensing means and in which are provided: a plurality of conveyor elements, arranged side by side and oriented according to the direction of transport of said ceramic tile or slab, to define in their upper part a mobile resting surface of predetermined width, intended to receive the powdered enamel released by said dispensing means to form continuously a layer of said enamel powder; power members, associated with each of said conveyor elements, which are configured to be selectively activated to impart a predetermined incremental advance to the relative conveyor element, such that a dosed quantity of enamel powder is induced to falling, by gravity, onto the underlying ceramic tile or slab in transit with suitably synchronized motion; - an electronic processing unit, in which a scheme corresponding to said drawing or decoration for said tile or slab is stored in digital form; - an actuation unit, controlled by said electronic processing unit, configured for stepping each conveyor element present in said metering unit, in phase relation with the advance of the mentioned ceramic tile or slab, to deposit on the surface of said ceramic tile or slab dosed quantities of powder enamel, with the necessary thickness, in accordance with the aforementioned drawing or decoration scheme. - dispensing means, provided with a tray for containing said powder enamel, in said tray being provided at least one lower blade opening, extended transversely to the aforementioned tile or slab, for gravity release of the aforementioned powder enamel; - a metering unit, arranged below said dispensing means and in which are provided: a plurality of conveyor elements, arranged side by side and oriented according to the direction of transport of said ceramic tile or slab, to define in their upper part a mobile resting surface of predetermined width, intended to receive the powdered enamel released by said dispensing means to form continuously a layer of said enamel powder; power members, associated with each of said conveyor elements, which are configured to be selectively activated to impart a predetermined incremental advance to the relative conveyor element, such that a dosed quantity of enamel powder is induced to falling, by gravity, onto the underlying ceramic tile or slab in transit with suitably synchronized motion; - an electronic processing unit, in which a scheme corresponding to said drawing or decoration for said tile or slab is stored in digital form; - an actuation unit, controlled by said electronic processing unit, configured for stepping each conveyor element present in said metering unit, in phase relation with the advance of the mentioned ceramic tile or slab, to deposit on the surface of said ceramic tile or slab dosed quantities of powder enamel, with the necessary thickness, in accordance with the aforementioned drawing or decoration scheme.