Abstract: A surface-emitting device includes: a light-emitting diode substrate including a supporting substrate, and a light-emitting diode element placed on one surface side of the supporting substrate; a sealing member placed on a light-emitting diode element side surface of the light-emitting diode substrate, and configured to seal the light-emitting diode element; and a diffusion member placed on the sealing member, on an opposite surface side to the light-emitting diode substrate side, wherein a haze value of the sealing member is 4% or more, and a thickness thereof is thicker than a thickness of the light-emitting diode element.

Abstract: A planar light source device includes a light diffusing portion and a light reflecting portion in this order. The light diffusing portion has light transmissivity and light diffusivity. Reflectance of the light reflecting portion with respect to light of a particular wavelength entering at an angle of incidence of 0° is 80% or higher. The reflectance of the light reflecting portion with respect to at least part of light of the particular wavelength entering at an angle of incidence of which an absolute value is greater than 45° is less than 50%.

Abstract: A diffusion member includes a first layer and a second layer, in this order, wherein the first layer has a light transmissivity and a light diffusivity, in the second layer, a reflectance of light increases as an absolute value of an incident angle with respect to a first layer side surface of the second layer decreases, and a transmittance of light increases as an absolute value of an incident angle with respect to a first layer side surface of the second layer increases.