"We are working closely with authorities in Jizan to make sure that justice will be given to Agnes Mancilla," the ministry said in a statement.
The victim is in "serious but stable condition" in hospital and Saudi police have arrested her female employer, who has not been named, it added.
Mancilla had worked in Saudi Arabia since 2016 "but was repeatedly physically abused by her lady employer" who also failed to pay her salary, the statement said, citing Edgar Badajos, the Philippine consul in the Saudi city of Jeddah.
The report is the latest incident of alleged mistreatment of Filipino workers in the Middle East.
He banned Filipinos from going to work in the Gulf state, one of several Middle East countries that host, in total, more than two million Filipino workers. Duterte claimed that Arab employers routinely rape their Filipina workers, force them to work 21 hours a day, and feed them scraps.
Last week Duterte said Kuwait had agreed to his demands to improve the working conditions of Filipinos, following negotiations between the two countries on a labour accord.
One of his key demands is that Filipino workers be allowed to keep their mobile phones and passports -- which can be confiscated by employers under current conditions.
Duterte said he would visit Kuwait to witness the signing of the agreement, without giving an exact date.