The purpose of this research is to examine the production of Apontamentos de Matemática, written by Dom Ireneu Penna, professor and intellectual authority. Apontamentos are a set of four textbooks used at Colégio de São Bento of Rio de Janeiro from 1967 to 2001, based on the New Math Movement and on Georges Pappy s ideas. The analysis of the history of the Apontamentos follows an hermeneutic approach, considering that textbook analysis is a process of interpretation of the different elements around it. The methodology adopted is documental analysis. This work analyses the historical, educational and political context where the production of the Apontamentos took place; identifies the agents involved and their influence in the production circuit; analyses the formal aspects that compose it, such as cover, preface and summary, identifying their singularities and relations with the production itself; and analyses the text and its relations with the sources used by the author, highlighting his alignment with the guidelines of Mathematics Education indicated by Unesco in 1966. It s also shown that, even though Dom Irineu has written himself several paragaphs in it, Apontamentos is an adaptation of the Belgium textbooks Mathématique Moderne, by Pappy. In the end the conclusion indicates that the production of Apontamentos is a flash of the fight of a teacher for an ideal of modernisation in pedagogycal-mathematical method in order to provide tools for thought, being logical and coherent with his conception of progress in Science.