Disclosed are: a diaryliodonium salt mixture which is a precursor of a BF4 salt or the like of a diaryliodonium compound, can be produced in the form of crystals at ambient temperature, can be purified in a simple manner, can be produced with high efficiency, and can be induced into a BF4 salt or the like salt that has excellent solubility in a monomer or the like; and a process for producing the diaryliodonium salt mixture. Also disclosed is a production process which can achieve good yield and can produce reduced amounts of byproducts, and is therefore applicable to the industrial mass production of a diaryliodonium compound. The diaryliodonium salt mixture is characterized by containing at least two specific diaryliodonium salts.