[en] In this work the possibility of exploiting the magnetooptical Kerr effects in the vacuum-ultraviolet spectral region (VUV) is examined. The Kerr effects are compared with other magnetooptical effects. In order to achieve a deeper understanding of the different magnetooptical effects, these are derived from Maxwell's equations. The main issue of this analysis concerns the dielectric tensors ε and its off-diagonal element ε_xy. Measurements of the longitudinal magnetooptical Kerr effect (L-MOKE) are presented. The angular dependance of this effect was measured for an iron single crystal at the Fe 3p resonance. The rotation of the polarization plane of the reflected light in the vicinity of the Fe 3p resonance can be several degrees, which is large compared to the visible spectral region where the angles of rotation are only fractions of a degree. Two layer systems of iron-chrome-iron were investigated using the transverse magnetooptical Kerr effect (T-MOKE) and it was found that T-MOKE in the VUV is suitable for measurements with lateral resolution. Furthermore this layer system was examined using angle and energy dependent T-MOKE at the Fe-2p-resonance (about 700 eV) and at the Cr-2p-resonance (about 575 eV). (orig.)