J'ai trouvé ça :
The Russian M39 are compatible with infinity focus on EOS cameras as long as the adapter is of the proper lenght.
You can also do what many other people do, that is, to buy a M39-M42 stepup ring and apply it to the lens, and then use a M42 to EOS adapter. If the stepup ring is not longer than the threaded mount on the lens, this should also ensure infinity focus. This way, you can also use the advantage of a chipped M42-EOS adapter.