Tangalle – Advanced Technological institute is a newly established institute among most other institutes under SLIATE. In 2014, three full-time courses were started in the new building located at Yayawatta, Netolpitiya, Tangalle. Initially HND in Accountancy, HND in English and HND in Information Technology were started. In addition to these full-time courses, HNDA (P/T) and HNDE(P/T) courses are also being conducted.
As SLIATE descend from Technical Colleges, HND in Accountancy & HND in English part time courses were conducted at Technical College in Beliatta a long time ago. In 2008, the ATI section moved to Tangalle and the above part time courses were conducted at Tangalle Maha Vidyalaya (Boys) until the new building for the ATI was constructed. New two storied building for ATI Section Tangalle has been constructed under the HETC project of the World Bank. Further in the next phase of the project, another building is planned to be constructed which will include a fully-fledged library, Canteen, Gymnasium etc.
Furthermore, In August 2019, through a gazette notice, this Advanced Technological Institute Section was declared an Advanced Technological Institute.