To provide a safer method for manufacturing a β-type sialon phosphor.

The method for manufacturing a β-type sialon phosphor includes a step of mixing phosphor raw materials, a step of firing a mixture obtained by the mixing step, and a step of cleaning the fired body obtained in the firing step. In the cleaning step, an aqueous solution A of a fluoride which is solid at 20°C and has a solubility at 20°C of 0.01-400 g/100 ml of water and an aqueous solution B containing at least one of inorganic acid except hydrofluoric acid are used for cleaning.