PURPOSE: To maximize the variation in the spontaneous polarization of the ferroelectric material for higher outputs by defining the ferroelectric thin film in a block which constitutes the minimum unit required for operating a ferroelectric thin film element.

CONSTITUTION: A tantalum film 2 and platinum film 3 are formed as a lower electrode on a silicon substrate 1. A lead titanate-zirconate thin film 4 is formed thereon as a ferroelectric thin film. A bias voltage is applied to the silicon substrate 1 while the lead titanate-zirconate thin film 4 is being formed on the lower electrode. After the formation of the lead titanate-zirconate thin film 4, the tantalum 2, platinum 3 and lead titanate-zirconate 4 films are subjected to RIE(Reactive Ion Etching) to form a large number of square patterns, 200μm or below in width and 200μm or below in length. Subsequently, heat treatment is performed to turn the lead titanate-zirconate thin film 4 into a single crystal.