There is provided a method for industrially producing a phosphor with high performance, in particular, high brightness. There is also provided a nitrogen-containing alloy and an alloy powder that can be used for the production method. A method for producing a phosphor includes a step of heating a raw material for the phosphor under a nitrogen-containing atmosphere, in which an alloy containing two or more different metal elements constituting the phosphor is used as the whole or part of the raw material for the phosphor, and in the heating step, the heating is performed under conditions such that the temperature change per minute is 50 DEG C or lower. It is possible to suppress the rapid progress of a nitridation reaction in heat treatment in producing the phosphor using an alloy for a phosphor precursor as the whole or part of the raw material, thereby industrially producing the phosphor with high performance, in particular, high brightness.