Telescopic apparatus for a cooking appliance for holding a food carrier that can be retracted and extended by means of the telescopic apparatus relative to a cooking chamber of the cooking appliance, in parallel with a longitudinal axis of the telescopic apparatus, comprising a mounting rail for detachably mounting the telescopic apparatus on a side grid in the cooking chamber in a mounted state of the telescopic apparatus and a middle rail mounted on the mounting rail so as to be longitudinally movable relative to the mounting rail and a holding rail mounted on the middle rail so as to be longitudinally movable relative to the mounting rail and the middle rail, for holding the food carrier, wherein the middle rail and the holding rail can be transferred back and forth between a retracted position in which the telescopic apparatus can be arranged completely in the cooking chamber, and an extended position in which the holding rail of the telescopic apparatus is arranged at least partially outside the cooking chamber in the mounted state of the telescopic apparatus, wherein the mounting rail and the middle rail are designed to correspond to one another in such a way that the telescopic apparatus can be mounted and removed on the side wall or the side grid solely by means of the mounting rail in the retracted position, characterised in that a blocking part is arranged on the middle rail, which blocking part is in engagement with the side grid in the mounted state of the telescopic apparatus in the extended position and when it is transferred from the retracted position to the extended position and vice versa, and therefore the telescopic apparatus is held non-detachably on the side grid solely through the aforementioned transfers or the presence of the extended position non-detachably on the side grid. a mounting rail for detachably mounting the telescopic apparatus on a side grid in the cooking chamber in a mounted state of the telescopic apparatus and a middle rail mounted on the mounting rail so as to be longitudinally movable relative to the mounting rail and a holding rail mounted on the middle rail so as to be longitudinally movable relative to the mounting rail and the middle rail, for holding the food carrier, wherein the middle rail and the holding rail can be transferred back and forth between a retracted position in which the telescopic apparatus can be arranged completely in the cooking chamber, and an extended position in which the holding rail of the telescopic apparatus is arranged at least partially outside the cooking chamber in the mounted state of the telescopic apparatus, wherein the mounting rail and the middle rail are designed to correspond to one another in such a way that the telescopic apparatus can be mounted and removed on the side wall or the side grid solely by means of the mounting rail in the retracted position, characterised in that a blocking part is arranged on the middle rail, which blocking part is in engagement with the side grid in the mounted state of the telescopic apparatus in the extended position and when it is transferred from the retracted position to the extended position and vice versa, and therefore the telescopic apparatus is held non-detachably on the side grid solely through the aforementioned transfers or the presence of the extended position non-detachably on the side grid.