The person was in the service of the 18th dynasty Queen Hatshepsut, the most powerful female pharaoh and who ruled for 21 years from 1479 to 1458 BC.
The burial chamber of about 3.5 square metres and 1.5 metres high, is one of the first to have been entirely decorated with paintings from the era, said the Spanish Egyptologist who made the discovery, Jose Manuel Galan.
Dr Galan is head of the team that has been carrying out excavation work for several years in the Dra Abu El-Naga necropolis on the west bank of Luxor for the CSIC, a project financed since 2004 by the Caja Madrid foundation.
Archaeologists in 2007 identified a mummy found in a tomb in the Valley of the Kings in Luxor about a century ago as that of Hatshepsut, who declared herself pharaoh after the death of her husband and half-brother Tuthmosis II and was known for sporting a false beard and dressing like a man.