Due to the high thermal and chemical stability wide bandgap materials such as diamond and silicon carbide attract more and more attention. From one side such materials are interesting for electronics. Since they can find a lot of applications in harsh environment. From another point of view they are good matrixes to „freeze“ single atom system at room temperature, which can be used for quantum computing and not only. I am going to discuss one atom-like point center in diamond – nitrogen-vacancy (NV) defect. It is optically active center with non-zero spin. NV center can be used as an optical marker for biological systems, due to nontoxicity and high biocompatibility of diamond. Also it can be used for magnetic field detection, including high sensitive NMR measurements.