Company subsidiary Oji Nepia will discontinue production and shipment of the products in September.
Oji Holdings says its annual output of baby diapers has declined to about 400 million in recent years from a peak of roughly 700 million in 2001.
Japan's government says children under the age of 15 accounted for less than 12% of the country's population in 2022 while 30% were 65 years or older.
Oji plans to boost production of diapers for adults in the domestic market while expanding its baby diaper business globally. The company will continue making baby diapers in in Indonesia and Malaysia.
According to data furnished by Osaka Marketing Co., Japanes baby diaper production was down 11.9% to 284,471 tons in 2023. Meanwhile, produciton of adult diapers was down 1.9% to 423,500 tons.