  A recent progress on laser cooling of molecules is summarized. Since the
development during 1980s for atomic species, laser cooling has been the very
beginning step to cool and trap atoms for frontier research on quantum
simulations, quantum sensing and precision measurements. Despite the complex
internal structures of molecules, laser cooling of molecules have been realized
with the deepened understanding of molecular structures and interaction between
light and molecules. The development of laser technology over the last decades
have also been a great aid for laser cooling of molecules because many lasers
are necessary to successfully cool the molecules. A detailed principle and
development of laser cooling of molecules as well as the current status of the
field are reviewed to give an introductory of the growing field of ultracold
molecular physics.
