An OLED illuminating device includes an OLED unit and an insulating unit. The OLED unit includes: a substrate having a top surface that includes a first zone provided with a terminal area; a light emitting element having a first electrode layer that includes a first terminal portion disposed on the terminal area, a second electrode layer that includes a second terminal portion disposed on the terminal area, and an organic light emitting multilayer structure; and a packaging cover partially covering the light emitting element in such a manner that the first and second terminal portions are exposed therefrom. The insulating unit covers the first and second terminal portions and is bonded adhesively to the terminal area.