Unfortunately, yes. Eren dies at the very end of the series. ... But the series ends in such a way that his death feels important in tying everything together. At the end of the manga, Mikasa, Armin, and Levi, as well as other fellow soldiers, are facing off against Eren and the source of all matter in battle.

Does Eren really die in AOT?

Eren has officially died, and with his death comes the end of the Titan power overall (saving all of those who were forcibly transformed in the penultimate chapter). After all of this, Mikasa takes Eren's head and buries him under the tree that they loved. As the series comes to an end, the world begins to move on.

Is Eren really dead 138?

At the end of Chapter 138, Mikasa was about to kill Eren. A flurry of events that had been occurring in the last few chapters and episodes suggested that Eren had taken a turn into the dark side. Hence, unless there are plot twits at play, it looks like Eren Yaegar is indeed dead.