Waste incineration fly ash could be successfully recycled into calcium phosphate hydrogel, a type of fast proton conductor. Various properties of the intermediate and calcium phosphate hydrogel from incineration fly ash were characterized and compared with those from calcium carbonate reagent. It was found that the intermediate from the incineration ash, calcium phosphate glass has lower strength than that from calcium carbonate reagent. The electrical conductivity of amorphous and crystallized hydrogel obtained from any raw material increases exponentially with increasing temperature. However, the amorphous hydrogel from incineration ash shows higher electrical conductivity than that from the reagent. On the other hand, the crystallized hydrogel from incineration ash has lower electrical conductivity and lower crystallinity than that from the reagent. Moreover, the difference in electrical conductivity between these crystallized hydrogels decreases with temperature. These experimental results suggest that the incineration fly ash is a useful calcium source for the synthesis of calcium phosphate hydrogel.