Martí Mitjà was born in 1913 in Palafrugell, and died in 2012 in Cardedeu. He pursued a career at the Caixa de Pensions, where he began working in 1930. Throughout his career he held different positions and functions, such as head of local delegation, inspector or in charge of organizing literary competitions.

The collection consists of both his personal and professional documentation: correspondence, press files, photographs, brochures, various documentation from La Caixa de Pensions... it constitutes a source of special interest for students and researchers in economic, social and institutional history, as well as for the study of the labor and associative world of the 20th century.