In order to provide a filler suitable for a dental glass ionomer cement which can easily be manufactured using a common inorganic powder as a raw material and which yields a cured cement having high strength when the filler is blended in a dental glass ionomer cement composition, and a method for manufacturing the filler, the present invention is configured as a filler for a dental glass ionomer cement, in which a compound having a carboxyl group is bonded via a silicon atom. The method for manufacturing the filler comprises causing a carboxylic acid having an unsaturated double bond which is not a (meth)acrylate compound to bond to an inorganic powder which is surface-treated by a silane treatment material having an unsaturated double bond.
