The service said: “We have now left the scene, however, we will continue to inspect and monitor the site at regular intervals overnight to ensure the fire remains out.”
It added that the building’s structure has been “badly damaged”, and spoke of “concerns” over its stability.
The blaze, which broke out on Friday morning, began in the basement of the hotel.
An investigation into the cause of the fire will begin this morning.
At the height of the incident, 12 fire engines were on scene, as well as officers and specialist appliances and vehicles. West Sussex Fire and Rescue and Sussex Police were also on hand to provide support.
Six people were treated for minor injuries, with one patient admitted to Eastbourne hospital with reports of “breathing difficulties”.
There is a permanent cordon around the building, and road closures still remain in place.
Meanwhile, Eastbourne Borough Council is providing accommodation for those who live in neighbouring properties.