A blue organic electroluminescent device including a first reflective member (21), a second reflective member (23) and an emitting layer (22) arranged between the first and the second reflective members (21), (23); wherein the emitting layer comprises a first organic luminescent medium emitting light with a blue first peak wavelength and a second medium emitting light with a second peak wavelength; each of lights emitted from the first and second organic luminescent mediums are interfered with between the first and second reflective members (21), (23) to enhance light emitted from the first organic luminescent medium; and light taken out to outside has a first peak wavelength and a second peak wavelength that satisfy the following relationship: I1>I2.times.5, I1