Provided are: an organic/inorganic composite, and a manufacturing method therefor; and a dental material and bone substitute material manufactured using the organic/inorganic composite. The organic/inorganic composite includes: (A) 100 parts by mass of a thermoplastic resin containing as a main component at least one kind selected from a polyarylketone resin and a polysulfone resin; and (B) 60 to 300 parts by mass of an inorganic particle mixture dispersed in the thermoplastic resin, in which the inorganic particle mixture contains inorganic particles each having a particle diameter of from 200 to 700 nm at a content of 25 vol % or more, and inorganic particles each having a particle diameter of from 40 to 100 nm at a content of 10 vol % or more.