With the requirement of Power Factor (PF) are being set to standards, commercial electrical products must pass globally recognized standards such as the European EN61000-3-2 and the Energy Star Program Requirements to be sold around the globe. Under the consideration for minimum Total Harmonic Distortion (THD) and maximum PF, the Boost Power Factor Correction (PFC) topology is used to meet the demands for applications with a 400 V high voltage output. To take advantage in the recent advance in planar passive components, a planar ferrite core transformer is used with the proposed Boost PFC circuit, which allows high power density and decreases the overall volume of the system. This thesis begins with the discussion regarding the relationship and physical significance between THD and PF. Comparisons between passive and active PFC circuits, Buck PFC circuits and Boost PFC circuits, single stage PFC circuits and multi stage PFC circuits, are given respectively. This thesis also compares the differences in circuit operation regarding the continuity of transformer current. The operations of each circuit blocks are given in detail, and a small-signal model is derived for analysis. The metal core planar transformer technology is also introduced. Finally, in order to verify the design proposed in this thesis, circuit simulation and actual measurement are conducted. Simulation results suggest that the proposed PFC circuit provides sufficient PF and THD ratings for many major international standards under various input voltage and output loading conditions. Its high power conversion efficiency also satisfies the need for commercial electrical products requiring high input voltage and demands high power consumption.