The utility model relates to a lunch box which comprises a box shell and a box cover, wherein the box shell is formed by attaching an internal heating layer and an external insulating layer; the bottom end of the external insulating layer is provided with a base, and the base and the bottom surface of the external insulating layer are attached into a whole; the internal heating layer is internally provided with an electrical heating wire; the base is internally provided with a rechargeable battery used for supplying power to the electric heating wire; the external wall of the box shell is provided with a switch connected in series between the electric heating wire and the rechargeable battery; the side wall of the base is provided with a mains supply interface used for charging the rechargeable battery; the contact surface of the external insulating layer and the box cover is higher than that of the internal heating layer and the box cover; the box cover is hermetically fastened with the box shell through a sealing clip; the side wall of the base, adjacent to one side of the rechargeable battery, is provided with a charging indicator light; and two opposite sides of the outer wall of the box shell are respectively fixedly connected with a handle; and the top surface of the box cover is provided with a rotatable lifting handle. By utilizing the charging and discharging principle of the rechargeable battery, self heating at any time and any place of the lunch box can be realized; and the lunch box is simple in structure and is convenient and practicable.