No. He's in cryogenic status, the same place where the Halo series began. 

He isn't dead

what so halo 1 is realy after halo 3 anyone else can aweser it dosnt need to be CosmicSpiral but he can if he wants 

No, Chief is NOT dead he's just taking a Cryo-Nap in space. Why would you think that Halo 1 is after Halo 3? In Halo 1 the Covenant don't know how to get to Earth, But in 2, 3 & ODST the Covenant and UNSC are engaged in combat on the surface an in space. How could it possibly be afterward Halo 3? 
 
Halo: Reach (2010) - Covenant Destroy Reach, Pillar of Autumn flees with the assistance on Noble Team and finds one of several "Halos" 
Halo: Combat Evolved (2001) - Pillar of Autumn crashes on Halo, Master Chief kills lots of Aliens and discovers the Flood, Blows up that Halo. 
Halo 2 (2004) - Covenant Attack Earth for the first time, Chief kills more aliens and follows to ANOTHER Halo, Fights Covies and Flood, Elites Betrayed and join Humans, Covenant Capital Captured by Flood. 
Halo 3: ODST (2009) - In between 2 & 3, Follows a group of Orbital Drop Shock Troopers in Occupied New Mombassa, No Master Chief.  
Halo 3 (2007) - Covenant Have attacked Earth Again, Chief kills more aliens, Flood show up and ruin everyone's day, Elites arrive to assist Humans, Elites Destroy most of Africa, Humans and Elites go and fight Covenant on the Arc (Big Halo Factory/Control Center), Humans and Elites win, Arbiter and Chief try to escape, only Arbiter makes it back to Earth, Chief trapped in space, decides to take nap, The End... or is it?
 

As has now been stated, he is not dead just floating through space until he crashes on some planet and gets woken up so we can have halo 4.

Halo 4...still not dead.