The Manolis Triantafyllidis Collection belongs to the Institute of Modern Greek Studies (Manolis Triantafyllidis Foundation) and comprises 2428 volumes, mainly on education and philosophy, including quite a few rare editions. The collection also includes manuscript works by Manolis Triantafyllidis.

Almost all the material has been digitised by the Library, but only part of it is available in the Psifiothiki.  The Central Library has some pamphlets by Triantafyllidis that have not yet been digitised.