The Australian team was exploring a much older tomb, when they stumbled across the door concealed by a statue. They found the mummy and three coffins.
It's thought the mummy, which has been described as one of the best mummies ever preserved, is 2,500 years old.
"I believe this discovery can enrich us about two important periods in our history," one archaeologist said.
Expert Zahi Hawass said the mummy and coffins would tell them important
information about the
The mummy is covered with turquoise blue beads, which have usually deteriorated with age, and is wrapped in black cloth.
Experts don't know who the mummy is yet, but they think it belongs to a middle class official of the time.