A microchip thin film transformer which is composed of an I-shaped [CoZrNb/SiOχ]m magnetic layer and wound with Cu thin film coils fabricated by using a mask vacuum evaporation and sputtering composited process has been investigated. Comparing the CoZrNb core with [CoZrNb/SiOχ]m core of thin lm transformer, it is shown that the multilayer thin films have more advantages than a single magnetic layer in their of soft magnetic properties, especially the permeability (μ) and coercivity (He). The microchip transformer has a relatively high inductance of 0.4-1.0μH for a ratio of primary turns to secondary coil turns of 3:1 and 3:2, and has a high Q value of 4-12. The thin film transformer can be operated in an integrated micro-switching converter at a frequency between 1kHzand 10MHz.