Radio sky surveys with LOFAR telescope

The International Low-Frequency Array (LOFAR) was designed as a highly efficient radio interferometer to perform sky surveys in the poorly explored low-frequency part of the electromagnetic spectrum. We briefly describe the instrument and review some recent observational results from the first and shallow Multifrequency Snapshot Sky Survey, as well as from the current much deeper LOFAR Two-metre Sky Survey. These results show the enormous potential of LOFAR for studying active galactic nuclei and star-forming galaxies, intergalactic magnetic fields, and cosmic ray propagation processes in galactic disks. We also mention LOFAR deep surveys and subarcsecond resolution surveys possible in future.