A lab muffle furnace heating element is resistance wire coil form placed in grooved refractory. the heating element is a combination of ceramic fiber and refractory bricks ensured robustness with optimum thermal efficiency. the door of this muffled furnace is a heavily insulated door rested on heavy hinges movable on a side. A door limit switch shall be provided isolates power from the elements whenever the door is opened. the case of this furnace is fabricated from mild steel sheet suitably reinforced.