A coating apparatus (1) and method are disclosed for coating tablets in a rotating drilled container (2) at the outlet of which a rotating annular element (11) operates that is coaxial with the container, in which in an initial transition phase the annular element rotates in a direction that is opposite the rotation direction of the container to retain the tablets inside the container, forming a bed of tablets until a desired level is reached, and in a stationary phase the annular element rotates in a direction that is the same as the rotation of the container to permit the exit of the tablets, until the quantity of tablets entering the container is the same that the quantity exiting.