The employee opened a package that contained an explosive substance, burning her hands and face.
It was intended for the IMF's European representative, Jeffrey Franks, who has been in his post since March 2015 after 24 years at the IMF.
International Monetary Fund chief Christine Lagarde on Thursday condemned the letter bomb of the fund office in Paris as a “cowardly act.”
“I condemn this cowardly act of violence and reaffirm the IMF’s resolve to continue our work in line with our mandate,” Lagarde said in a statement from Frankfurt, where she is attending a conference ahead of the Group of 20 finance ministers meeting in Baden-Baden.
Lagarde said the fund is “working closely with the French authorities to investigate this incident and ensure the safety of our staff.”