Superintendent of the hospital Dr Utpal Dan said the woman, an intern, was at the doctor's rest room at the Emergency last night when she was molested by the worker, Prasun Nayak.
Another doctor, who was also on duty noticed the incident, raised an alarm and caught Nayak red handed.
The superintendent said the man was taken to him where he admitted his crime and apologised in writing.
He was later handed over to the police.
Meanwhile, other interns demanded his strong punishment and security for doctors.