The objective of this paper is to apply a newly developed wavelet-based semblance filtering and eigenvalue analysis to investigate the geomagnetic variations in some micro-earthquakes that had occurred in the Korean Peninsula. The wavelet-based filtering showed improved results in delineating the geomagnetic variations in relation to earthquake events from their background field. In addition, the eigenvalues analysis was also useful for the interpretation of three components geomagnetic fields during the earthquake events. The wavelet-based semblance analysis showed a prominent result for short-term geomagnetic variation related to the earthquake event, and the eigenvalue analysis was feasible to long-term geomagnetic variation. Considering the fact that the basement rock of the Korean Peninsula has a highly resistive electrical structure, it seems to be possible for small magnitude earthquakes to generate some distinguished geomagnetic variations.