The 39-year-old said that the Finn has been a model professional since signing on two years ago, but believes that now is the time to concentrate on the team's future.
When asked if he begrudged Raikkonen's decision, Boullier told AUTOSPORT: "Not at all. We've been working with an amazing racer, who scored points for the team 27 times in a row, won two races, put motivation at a very high level at Enstone, and got on very well with his team-mate.
"Of course this is a disappointment to all of us, and we're sure you will agree that Kimi has been nothing but brilliant since he joined us.
"Now, it's time to think about the future. We've had [Michael] Schumacher, [Fernando] Alonso, Raikkonen. New champions will join the list here soon I'm sure."
The Frenchman is now tasked with filling Raikkonen's seat for next season, but he insists that he is no rush to sign a new driver.
"We are currently in discussion with a few people and will make a decision shortly," he added.
"We are in the privileged position of being the most desirable team on the grid with a seat available, so we are therefore in no rush to announce anyone without establishing what will be the best for our team and the future."
Sauber's Nico Hulkenberg is the current favourite to succeed Raikkonen.