Abstract: There is provided a warming tray, especially suitable for installation in a food preparation working surface, including a top layer, having an upper surface and a lower surface, made of a material selected from the group of natural and/or artificial marble, or marble-like stones, synthetic stones, glass, ceramic, stainless steel or other metals or alloys, an intermediate thin layer contacting the lower surface of the top layer, made of thermally sensitive material having electrical terminals extending along edges of the intermediate layer, for applying electrical power thereto, and a thermally insulating layer contacting the lower surface of the intermediate thin layer.