He checked into rehab at the end of August.
Ben Affleck has finished his time in rehab and has taken to social media to thank his family.
In the Instagram post, he said that he is still working hard with sobriety and is going to continue outpatient care.
He said: "This week I completed a 40 day stay at a treatment centre for alcohol addiction and remain in outpatient care.
"The support I have received from the family, colleagues and fans means more to me than I can say. It's given me the strength and support to speak about my illness with others.
"Battling addiction is a lifelong and difficult struggle... I am fighting for myself and my family. So many people have reached out on social media and spoken about their own journeys with addiction. To those people, I want to say thank you. Your strength is inspiring and supporting me in ways I didn't think was possible. It helps to know I am not alone."
He finishes by saying: "I hope down the road I can offer an example to others who are struggling."
You can read the full statement here:
