Abstract: Provided is a filler for dental glass ionomer cements, the filler to a surface of which a compound(s) having a carboxyl group(s) is/are bound via a silicon atom, for the purpose of providing: a filler suitable for dental glass ionomer cements that can provide a hardened cement having a high strength by being mixed with a dental glass ionomer cement composition, the filler that can be easily manufactured from a general inorganic powder as a raw material; and a manufacturing method of the filler for dental glass ionomer cements. The manufacturing method includes binding a carboxylic acid having an unsaturated double bond(s) exclusive of a (meth)acrylate compound to an inorganic powder whose surface is treated with a silane coupling agent having an unsaturated double bond(s).