A lens-mounted light emitting unit comprising: a base plate; multiple LED elements placed on the base plate; and a lens unit having a shape of a body of revolution about a normal line of the base plate as a symmetry axis of revolution which passes through substantially the center of gravity of the multiple LED elements, in which the multiple LED elements include LED elements of multiple light colors, while the lens unit color-mixes and emits light from the LED elements, wherein the lens unit comprises: an emitting surface perpendicular to the normal line of the base plate; a reflecting surface extending convexly toward the base plate from the emitting surface; a side incident surface which is replicated toward the emitting surface from an end of the base plate side of the reflecting surface; and an upper incident surface which bounds an end of the side incident surface which does not contact with the reflecting surface, characterized in that, the different LED elements (12A, 12B) have respective positional offsets from the lens center axis, and assuming an arbitrary contact point between the side incident surface and the upper incident surface, and that light from an LED element farthest from the contact point is refracted at the contact point to form a light path intersecting the emitting surface at an intersection point, the emitting surface inside a circle with a radius formed by continuously connecting such intersection points has a diffusion angle larger than the diffusion angle of the emitting surface outside the circle, wherein as a means to allow the emitting surface to have different diffusion angles, a differently shaped mi-cro-order concavo-convex shape is formed on a surface of a diffusion sheet or directly on the surface of the lens unit. a base plate; multiple LED elements placed on the base plate; and a lens unit having a shape of a body of revolution about a normal line of the base plate as a symmetry axis of revolution which passes through substantially the center of gravity of the multiple LED elements, in which the multiple LED elements include LED elements of multiple light colors, while the lens unit color-mixes and emits light from the LED elements, wherein the lens unit comprises: an emitting surface perpendicular to the normal line of the base plate; a reflecting surface extending convexly toward the base plate from the emitting surface; a side incident surface which is replicated toward the emitting surface from an end of the base plate side of the reflecting surface; and an upper incident surface which bounds an end of the side incident surface which does not contact with the reflecting surface, characterized in that, the different LED elements (12A, 12B) have respective positional offsets from the lens center axis, and assuming an arbitrary contact point between the side incident surface and the upper incident surface, and that light from an LED element farthest from the contact point is refracted at the contact point to form a light path intersecting the emitting surface at an intersection point, the emitting surface inside a circle with a radius formed by continuously connecting such intersection points has a diffusion angle larger than the diffusion angle of the emitting surface outside the circle, wherein as a means to allow the emitting surface to have different diffusion angles, a differently shaped mi-cro-order concavo-convex shape is formed on a surface of a diffusion sheet or directly on the surface of the lens unit.