Point-contact spectroscopy of two-band superconductor MgB2

The progress in investigation of two-band superconductor MgB${}_2$ by the point-contact spectroscopy (PCS) is given. Results of study of superconducting gap temperature and magnetic field dependence for two-dimensional $\sigma$ and three-dimensional $\pi$ band and electron-phonon-interaction spectral function are presented. Correlation between the gap value and the intensity of the high T${}_c$ driving force – $E_{2g}$ boron vibration mode, is provided. PCS data on some nonsuperconducting transition metal diborides are surveyed for comparison.