A UV LED device includes a base, a lens disposed on the base, an adhesive unit, an LED chip unit, and an encapsulating member. The adhesive unit has multiple layers and is connected between the base and the lens such that the base, the lens and the adhesive unit cooperatively define an enclosed space. The LED chip unit is disposed in the enclosed space. The encapsulating member is disposed in the enclosed space, and encapsulates the LED chip unit. The encapsulating member is made of a material the same as a material of at least one layer of the adhesive unit.