A chip-scale infrared emitter package comprises an emitter chip and an enclosure. The emitter chip includes: a base having a central cavity; a membrane having a peripheral end, the peripheral end being isolated from a periphery of the central cavity by a loop-shaped gap; an electric resistor formed on the membrane; at least one slim supporting beam extending from the peripheral end of the membrane through the loop-shaped gap to the base; and a reflective material coated on the membrane. The enclosure has a can housing and a transparent window plate. The window plate cooperates with the can housing to define an enclosed vacuum chamber. The emitter chip is mounted in the enclosed vacuum chamber. The enclosed vacuum chamber has a pressure less than 0.01 torr.