Abstract: A multiple wavelength light emitting device is provided wherewith the resonance strength and directivity between colors can be easily adjusted for balance. This light emitting device comprises a light emission means 4 for emitting light containing wavelength components to be output, and a semi-reflecting layer group 2 wherein semi-reflecting layers 2R, 2G, and 2B that transmit some light having specific wavelengths emitted from the light emission means and reflect the remainder are stacked up in order in the direction of light advance in association with wavelengths of light to be output. Light emission regions AR, AG, and AB are determined in association with the wavelengths of light to be output.