A ferroelectric film is formed by an oxide that is described by a general formula AB.sub.1-xNb.sub.xO.sub.3. An A element includes at least Pb, and a B element includes at least one of Zr, Ti, V, W, Hf and Ta. The ferroelectric film includes Nb within the range of: 0.05.ltoreq.x<1. The ferroelectric film can be used for any of ferroelectric memories of 1T1C, 2T2C and simple matrix types.