Device (174) for heating, browning and / or roasting a food item, comprising: a first main panel (102, 302, 402, 502, 602, 802, 902, 1002) and a second main panel (104, 304, 404, 504, 604, 804, 904, 1004) in an opposite configuration； a first minor panel (106, 206, 306, 406, 506, 606, 806, 906) and a second minor panel (108, 208, 308, 408, 508, 608, 808, 908) in an opposite configuration, being joined the first minor panel and the second minor panel to the first main panel and the second main panel along the respective fold lines (110, 112, 114, 116, 216, 910, 912, 914, 916) to define, at least partially, an interior space (180)； an element (168) interactive with the microwave energy that is arranged above, at least a part of one of the first main panel, the second main panel, the first minor panel, and the second minor panel on one side of the panel respective facing the interior space (180)； and a first end panel (136, 1036) foldably attached to the first main panel (102, 302, 402, 502, 602, 802, 902, 1002)； characterized in that the first end panel includes a pair of opposite side edges (142, 144) that extend diverging from the first main panel (102, 302, 402, 502, 602, 802, 902, 1002).Dispositivo (174) para calentar, dorar y/o tostar un artículo alimenticio, que comprende: un primer panel principal (102, 302, 402, 502, 602, 802, 902, 1002) y un segundo panel principal (104, 304, 404, 504, 604, 804, 904, 1004) en una configuración opuesta； un primer panel menor (106, 206, 306, 406, 506, 606, 806, 906) y un segundo panel menor (108, 208, 308, 408, 508, 608, 808, 908) en una configuración opuesta, estando unidos el primer panel menor y el segundo panel menor al primer panel principal y al segundo panel principal a lo largo de las líneas de plegado respectivas (110, 112, 114, 116, 216, 910,. 912, 914, 916) para definir, por lo menos parcialmente, un espacio interior (180)； un elemento (168) interactivo con la energía de las microondas que está dispuesto encima, por
