Electric Box Kilns is a rugged extra heavy duty apparatus. The apparatus have heat seal door construction with door jambs and hinges that are fabricated of steel plate with two heavy duty door clamps, bolt hinges and a peep sight with cover. It has microprocessor temperature controller with digital display, provided with selector switch to shut off automatically at a predetermined temperature or maintain a preset temperature for any required length of time. These are durable, energy efficient multilayer interior lining, up to 7″ thick, consisting of energy efficient 2600o F rated insulating firebricks.