A phosphor which emits light having high brightness, serves as an excellent orange or red phosphor whose light brightness is less decreased when exposed to an excitation source contains a crystal phase having the chemical composition expressed by the general formula [1]: (1−a−b)(Ln′pMII′1−pMIII′MIV′N3).a(MIV′(3n+2)/4NnO).b(AMIV′2N3)  [1] wherein Ln′ represents a metal element selected from the group consisting of lanthanoids, Mn, and Ti; MnII′ represents a divalent metal element except the Ln′ element; MIII′ represents a trivalent metal element; MIV′ represents a tetravalent metal element; A represents a metal element selected from the group consisting of Li, Na, and K; 0 0, 0≦n, and 0.002≦(3n+2)a/4≦0.9.