A vacuum thermal cooker comprising an outer cooler, an inner cooker, a sealing lid unit and an insulating disc, the inner cooker being used for boiling food and then to be placed in the outer cooker sealed by the sealing lid unit and then the air in the outer cooker being sucked out by a separate simple sucking pump operated by hand, the interior of the outer cooker becoming vacuum so that the heat of the food and the inner cooker may be kept for a long period of time, not easily cooled off by function of the vacuum condition of the outer cooker.