This question was asked in our group by one of our community members Maanabh Borpujari. That, whether one can go to a different country for doing his / her internship while on APS.
If you have come directly to this article and wondering what is an APS, please read this article by Sanjay Kamath where he has explained what is an APS and related things : Autorisation Provisoire de Séjour - APS - Job Search Visa.
A person can come and go to and from France with an APS to any country. There is no restriction on this, as long as your APS is not expired. Of course, by APS we mean APS given to students at the end of your study (read our article linked on above paragraph).
This is precised in the circular of NORIMIM0900073C of 6 jully 2009. For more inforamtion, you can see this PDF : Circulaire NOR IMIK0900087C.
The visa issue
What you need to check however, is the visa requirement of your destination country. If you are still in the Schengen area, you can go to do an internship in that country with your APS of France, provided the duration is less than or equal to 90 days. If the duration of your internship is beyond 90 days, you will need to get a long stay visa of your destination country.
In case the country where you got your internship is not in the Schengen area, you have to check with their embassy for your VISA requirement. In case you are staying in the Schengen area, check with the embassy of your destination country still, as there is always a possibility that things have changed between now when I am writing this article and when you will be going out of France with your APS for an internship.
How to do once you got a job during your APS ? You need to ask for a status change to your prefecture.