A method for fabricating a ferroelectric device includes Step S1 of forming a polycrystalline electrode on or above a substrate in which a MOS transistor is formed, Step S2 of performing metal organic chemical vapor deposition to form an amorphous film of bismuth titanate on the polycrystalline electrode, and Step S3 of performing annealing at a temperature in a predetermined range to make the amorphous film be a polycrystalline ferroelectric film made up of a large number of bismuth titanate having a layered perovskite structure. Step S3 includes a sub-step of increasing a temperature of the amorphous film to a lower limit of the predetermined temperature range at a temperature increase rate at which crystal nuclei are not grown.