The sense of smell is one of the most important and oldest sensory organs in humans and other living beings. Philosophers have been involved in the sense of smell since ancient times. In recent years, several new theories of smell have emerged. American scientists Linda Buck and Richard Axel were awarded the Nobel Prize in 2004 for developing the coding of olfactory receptors and the analysis of the signal path to the center. The new quantum theory of smell is very different from previous theories. In detail, he tries to explain the reception and transmission of the quantized energy of the odorous particles to the center. It takes into account all the stages of the journey and the mechanisms of this transmission. It describes the transfer of odorant energy to the acceptor and receptor and further through the G protein to the transformation of intracellular energy. It draws attention to the mechanism of formation of receptor potential and action potential. It emphasizes the importance of intracellular regulatory mechanisms related to cell life and the simultaneous transfer of odorant energy to the center. It describes the role of calcium in the cell, signal amplification and encoding of olfactory information.