With our newly developed 1-MV field emission electron microscope, which has the brightest electron beam and the highest lattice resolution, we obtained new results about unconventional behaviors of quantized vortices in high-T_c superconductors. Although vortices have hitherto been observed only at the superconductor surfaces by conventional methods such as Bitter method, vortices inside high-T_c superconductors became observable by Lorentz microscopy using our 1-MV microscope. Making full use of this technique, we found various behaviors of vortices peculiar to high-T_c superconductors. [DOI: 10.1380/ejssnt.2004.17]