While no weapon was seen, the teller complied with his demands and he fled with an undisclosed amount of cash through the bank’s south door.
He was last seen fleeing in a vehicle, FBI spokeswoman Laura Eimiller said. But officials didn’t release a vehicle description on Thursday.
Police detectives arrived shortly after the teller activated the silent alarm, officials said.
Bank management placed a sign on the building window, notifying patrons that the bank was closed because of an emergency.
FBI investigators were looking into whether the man is responsible for other bank robberies, Eimiller said.
The robber was described as black, 205 pounds and 5 feet 5 inches tall. He wore a brown-and-beige beanie, a gray coat, a light-colored shirt and dark brown sunglasses.
The last bank robbery in Glendale was Jan. 14 at the Wells Fargo on Brand Boulevard.
The man in that robbery — dubbed the “Cooler Bandit” because of the nylon cooler or lunch bag that he carries to stow the money — tried to rob the bank by passing a demand note to the teller. But he abandoned his plans when the teller had trouble reading the note.
FBI officials said he has robbed seven banks in Southern California since August.
He is described as Latino or black, 16 to 25 years old, 5 feet 5 inches to 6 feet tall and 110 to 155 pounds. He has black hair and brown eyes, and has worn sunglasses with orange lenses and black-rimmed glasses.