This study focuses on the meaning and acquisition of the word thesaurus in monastic early medieval sources. The term essentially refers to objects characterized by strong symbolic, economic, cultural and sumptuary value. In the monastic Rules the word does not appear because the forms of accumulation and conservation of wealth were extraneous to the vow of poverty disciplined and emphasized by the drafters. With the growth of the monasteries, the promise of royal protection, the strengthening of ties with the power elites and the establishment of the institution of exemption, the treasures grow in importance, underlining the prestige acquired by the single monastery. The objects that compose it become a non-secondary element of what we can define the material memory of the monastic community, providing information on patrons, on the workshops active in the monastery, on the exchanges established with monastic foundations and with local communities, on donations from power groups active in the territory and finally on the subtraction and dispersion suffered.