An orange-emitting phosphor that emits at a high luminance when being excited by blue light emitted by a blue light-emitting diode is provided. This orange-emitting phosphor is an alkaline-earth metal silicate-based phosphor represented by a general formula of a (Sr1-xEux(1-y)Ybxy)O.SiO2. In the formula, a is provided as 2.9≦a≦3.1, x is provided as 0.005≦x≦0.10, and y is provided as 0.001≦y≦0.1. An orange-emitting phosphor that emits orange at a high luminance and produces no harmful gas is provided.