Abstract: An efficient heat insulating food heating chamber for a solar oven. The heating chamber includes a compartment and reflecting devices for concentrating solar radiation to elevate the temperature of the heating compartment. The heating compartment is defined by a lateral outer casing, an intermediate insulation and shock absorbing medium, and an innermost evacuated or partially evacuated glass casing. The inner most casing has a substantially angular inner wall for additional reflection of solar energy and a stepped surface for supporting transparent plates and a collection plate.