The present invention provides a red-light emitting phosphor that exhibits high luminous efficacy and emits light when excited by light having an emission peak in the blue region; and a method for manufacturing said phosphor. The phosphor represented by general formula (A): a(Si1-x-y,Tix,Mny)Fb and also characterized in that the half-band width of a diffraction pattern attributed to the (400) plane is not less than 0.2° determined by X-ray powder diffractometry. This phosphor can be manufactured by preparing a reaction solution consisting of an aqueous solution containing potassium permanganate and hydrogen fluoride, immersing a silicon source in said reaction solution, and reacting them for 20 to 80 minutes.