He was elected to be village head of Waluya village for two terms running from 2001 to 2012. In 2014, he ran for membership in the Bekasi Regency regional council (DPRD, Indonesian: Dewan Perwakilan Rakyat Daerah) and was elected to the position of Chairman of the Bekasi Regency DPRD in 2014.
In 2017 he successfully ran for office for the position of deputy regent of Bekasi Regency along with Neneng Hassanah Yasin. When Yasin was arrested on bribery charges by the Corruption Eradication Commission (KPK) in October 2018, Atmaja was appointed in her place. From 2019 until his death he was also chairman of the regional leadership council of the Golkar party.
Atmaja tested positive for COVID on July 1, 2021. He was initially treated at Jababeka hospital, Cikarang, in Bekasi but as it was over capacity he was sent to the Siloam Hospital in Kelapa Dua, Tangerang Regency, in western Java. He died there on July 11, 2021.
- "Profil Bupati Bekasi Eka Supria Atmaja yang Meninggal karena Covid-19, Putra Asli Daerah Berjuang dari Bawah Halaman all". KOMPAS (in Indonesian). 12 July 2021. Retrieved 12 July 2021.
- Warsono, Adi (11 July 2021). "Breaking News, Bupati Bekasi Eka Supria Atmaja Meninggal Dunia Karena Covid-19". Tempo (in Indonesian). Retrieved 12 July 2021.
- "OBITUARI: Eka Supria Atmaja, Bupati Bekasi yang Tutup Usia karena Covid". CNN Indonesia (in Indonesian). Retrieved 12 July 2021.
- "Profil Eka Supria Atmaja". tirto.id (in Indonesian). Retrieved 12 July 2021.
- Niman, Mikael. "Bupati Bekasi Terpilih Jadi Ketua DPD Golkar Secara Aklamasi". beritasatu.com (in Indonesian). Retrieved 12 July 2021.
- "Indonesian planned city at centre of corruption probe". London. BBC Monitoring Asia Pacific. 18 October 2018.