The present invention discloses a diffusion lens. The disclosed diffusion lens may include: an incidence surface which refracts incident light from a light source; a total reflection surface which totally reflects the light refracted at the incidence surface; a light emitting surface which emits the light from the incidence surface or the total reflection surface to the outside; and a light path changing surface which is installed between the total reflection surface and the light emitting surface to change a light path of the light Fresnel-reflected at the light emitting surface.
