PURPOSE: A light emitting device is provided to optimize optical efficiency by including a groove in the inner wall of the cavity of a housing. CONSTITUTION: In a light emitting device, lead frames(22,23) are spaced from each other. An LED chip(24) is electrically connected to the lead frames. A housing(21) comprises a cavity which exposes the lead frame to outside. A Zener diode(25) is electrically connected to the LED chip. Groove portions(221,231) are included in the inner wall of the cavity. The groove portion connects the Zener diode to the LED chip through a wire.
