The former Napoli coach is already working to improve his side ahead of his second season at the club after securing a return to Europe
The Nerazzurri finished fifth in Serie A to secure a return to European football after coming a disappointing ninth the previous campaign.
Mazzarri says he is satisfied with their showing but is already working to make sure they do better next time out.
"The return to Europe was not an obvious goal," he told La Stampa. "But I think it was a successful year, in which we did so many good things.
"I'm sure I'll be coach next year. I have a contract. I'm very pleased with the call I got from [president Erick] Thohir once we were certain to be in Europe.
"At a general level there were too many draws, we missed out on some victories when we threw away a lead. But I take responsibility.
"Even when we win, I'm not satisfied. We are already working with players for next season."