The woman, a 19-year old trainee, confessed to the police, the Mainichi reported.
She is accused of dumping the body of her newborn child in the empty lot sometime over the last four months.
A local discovered the child’s body on April 18 and reported it to authorities. An autopsy revealed the child was a boy who had died between one and four months ago. The cause of death has yet to be confirmed.
Kyodo News reported that the woman came to Japan in October and has been staying at her company's dormitory. Six other Vietnamese women also work at the company.
Around 328,000 Vietnamese are currently living in Japan as technical trainees, according to the Japanese immigration department.