It was reported that the intruder threatened Gaillard with a knife, forced her to give him the cello made by the master of musical instruments Francesco Goffriller in 1737.
The robber also stole the cellist's bow, made in 1825, and her mobile phone.
In her Facebook, Gaillard asked subscribers to help her find the cello.
According to the newspaper, Gaillard was not harmed in the attack.
The newspaper specifies that the cello was not the property of Guillard and belongs to the CIC bank. She leased the instrument in November 2015.
The police are currently investigating the incident.