A furnace for the treatment of food comprising a cleaning system having: - an interior room which can be closed by means of a door, - a heating device (76, 78) for heating the interior room, - means (22, 30, 38, 48, 50) for feeding and circulating fluid within the interior room and for releasing from the interior room, - a control device for controlling a cleaning cycle and being coupled with the means (22, 30, 38, 48, 50) for feeding, circulating and releasing, characterized in that - at least one support (52, 66) is provided into which a cleaning cartridge (56, 56', 72) can be placed, - wherein in addition to the cleaning cartridge (56, 56', 72) a clear rinsing cartridge (62, 74) can be placed into one support, - the cleaning cartridge (56, 56', 72) and the clear rinsing cartridge (62, 74) can be activated thermally and/or chemically for releasing cleaning agent and clear rinsing agent into the interior room, and - the cleaning agent contained within the cleaning cartridge (56, 56', 72) and the clear rinsing agent contained within the clear rinsing cartridge (62, 74) can be released substantially without any residuals at the latest by the end of the cleaning cycle, - wherein the support (52, 66) for the clear rinsing cartridge (62, 74) is arranged at a level above the support (58, 66) for the cleaning cartridge (56, 72) so that the clear rinsing cartridge (62, 74) can only be activated when reaching a higher liquid level than necessary for dissoluting the clear rinsing cartridge (56, 72), or - wherein spraying means (48, 50) are assigned at least to the support (52, 58) for the cleaning cartridge or the clear rinsing cartridge, so as to allow a selective spraying of the cartridge. - an interior room which can be closed by means of a door, - a heating device (76, 78) for heating the interior room, - means (22, 30, 38, 48, 50) for feeding and circulating fluid within the interior room and for releasing from the interior room, - a control device for controlling a cleaning cycle and being coupled with the means (22, 30, 38, 48, 50) for feeding, circulating and releasing, characterized in that - at least one support (52, 66) is provided into which a cleaning cartridge (56, 56', 72) can be placed, - wherein in addition to the cleaning cartridge (56, 56', 72) a clear rinsing cartridge (62, 74) can be placed into one support, - the cleaning cartridge (56, 56', 72) and the clear rinsing cartridge (62, 74) can be activated thermally and/or chemically for releasing cleaning agent and clear rinsing agent into the interior room, and - the cleaning agent contained within the cleaning cartridge (56, 56', 72) and the clear rinsing agent contained within the clear rinsing cartridge (62, 74) can be released substantially without any residuals at the latest by the end of the cleaning cycle, - wherein the support (52, 66) for the clear rinsing cartridge (62, 74) is arranged at a level above the support (58, 66) for the cleaning cartridge (56, 72) so that the clear rinsing cartridge (62, 74) can only be activated when reaching a higher liquid level than necessary for dissoluting the clear rinsing cartridge (56, 72), or - wherein spraying means (48, 50) are assigned at least to the support (52, 58) for the cleaning cartridge or the clear rinsing cartridge, so as to allow a selective spraying of the cartridge.