Kitchen appliance for processing food comprising: a container for containing food to be processed; a housing having a support adapted to sustain the container; a motorised driving unit adapted to rotate removable stirring or cutting means tools inside said container; a heating unit adapted to heat food to be processed inside the container; a lid for closing the container; one or more displaceable elements that cooperate with a portion or an appendage of said lid to prevent operation of the driving unit and/or heating unit by releasing an element triggering them, if the lid is not fitted to close the container in a predetermined manner; at least one sensor to detect the placement of the container on the support of the housing in a predetermined manner, said sensor being operatively connected to a control unit that prevents operation of the driving unit and/or heating unit if the container is not placed on the support of the housing in a predetermined manner; characterised in that it further comprises a container locking unit including at least one motorised movable tab having a retaining position, wherein it mechanically interferes with an opening of a skirt of the container, and a release position, wherein it does not interfere with said skirt of the container, wherein the at least one motorised movable tab moves to its retaining position upon activation by said control unit when the container is placed on the support in a predetermined manner and the lid closes the container in a predetermined manner; and in that said at least one movable tab in its retaining position mechanically prevents the opening of the lid of the container by interfering with at least one of said displaceable elements. a container for containing food to be processed; a housing having a support adapted to sustain the container; a motorised driving unit adapted to rotate removable stirring or cutting means tools inside said container; a heating unit adapted to heat food to be processed inside the container; a lid for closing the container; one or more displaceable elements that cooperate with a portion or an appendage of said lid to prevent operation of the driving unit and/or heating unit by releasing an element triggering them, if the lid is not fitted to close the container in a predetermined manner; at least one sensor to detect the placement of the container on the support of the housing in a predetermined manner, said sensor being operatively connected to a control unit that prevents operation of the driving unit and/or heating unit if the container is not placed on the support of the housing in a predetermined manner; characterised in that it further comprises a container locking unit including at least one motorised movable tab having a retaining position, wherein it mechanically interferes with an opening of a skirt of the container, and a release position, wherein it does not interfere with said skirt of the container, wherein the at least one motorised movable tab moves to its retaining position upon activation by said control unit when the container is placed on the support in a predetermined manner and the lid closes the container in a predetermined manner; and in that said at least one movable tab in its retaining position mechanically prevents the opening of the lid of the container by interfering with at least one of said displaceable elements.