Lead zirconate titanate (PZT) thin films were coated on Pt/Ti/SiO(2)/Si substrates by the sol-gel method and then crystallized by microwave annealing using a single-mode 2.45 GHz microwave irradiation system in the magnetic field. The crystalline phases and microstructures as well as the ferroelectric properties of the PZT films were investigated as a function of the elevated temperature generated by microwave irradiation, and the phase transition in the crystallization of the PZT thin films was discussed. X-ray diffraction analysis and transmission electron microscopic study indicated that the crystallization to the perovskite phase in the PZT films by microwave annealing started at 430 degrees C, and mostly finished at 450 degrees C for 30 min. The remanent polarization of the PZT films increased with the increasing annealing temperature, and the lowest temperature required to obtain perovskite PZT films with good ferroelectric properties in the microwave irradiation processing was 450 degrees C, which is much lower than that in conventional thermal processing.