In general, according to one embodiment, an illumination device includes a light emitting unit, a connection unit, a containing unit, and a second sealing unit. The light emitting unit includes a first substrate, a second substrate, an organic electroluminescent element, and a first sealing unit. The organic electroluminescent element is provided between the first substrate and the second substrate. The first sealing unit seals circumferential edge portions between the first substrate and the second substrate. The connection unit supplies power to the organic electroluminescent element. The containing unit has a space being airtight in an interior of the containing unit. The containing unit contains the light emitting unit inside the space. The second sealing unit is provided in the containing unit. The second sealing unit seals between a portion of the unit extending outside the containing unit and the containing unit.