A display device is provided and a display unit of the display device includes a light emitting unit and a light converting layer disposed on the light emitting unit. The display unit emits an output light under an operation of the highest gray level, the output light having an output spectrum. An intensity integral of the output spectrum from 380 nm to 493 nm defines as a first intensity integral, an intensity integral of the output spectrum from 494 nm to 580 nm defines as a second intensity integral, a ratio of the first intensity integral over the second intensity integral defines as a first ratio, and the first ratio ranges from 5 to 20.