A device for aquatic organism attachment and growth that has an excellent strength and inhibits dropping of its fixation leg part from the mount hole on the base disk side, and that can be manufactured at low cost. The device consists of a fired body obtained by subjecting a raw material mixture composed mainly of steel making slag and a metallic-Al-containing material, optionally blended with metallic iron and/or iron-oxide-containing powder, clay, etc., to molding and firing. Iron contents are melted and solidified by high-temperature firing realized by a thermite reaction between the metallic Al and the iron oxide, and low-melting-point compounds are formed depending on the raw material components, thereby attaining exhibition of strength leading to excellent strength. Further, pores are formed at the production of the fired body, so that the surface is provided with an appropriate roughness. This surface roughness inhibits dropping of the fixation leg part from the mount hole on the base disk side.
