He held numerous ecclesiastical offices in the Catholic Church and was associated with the Kraków Academy for his entire career.

In Padua, Brożek became friends with Giovanni Camillo Glorioso, who in 1613 had succeeded Galileo in the chair of mathematics at the university.

Between 1627 and 1635, Brożek wrote reports to Rome and made ten trips to Warsaw, advocating for university independence and petitioning the royal court to defend their rights.

[5] In 1639 he donated his extensive personal library to the university and also provided a substantial sum of money to purchase additional books and instruments.

Among the problems he addressed was why bees create hexagonal honeycombs; he demonstrated that this is the most efficient way of using wax and storing honey.

[8] He contributed to a greater knowledge of Nicolaus Copernicus' theories and was his ardent supporter and early prospective biographer.

Around 1618 he visited the chapter at Warmia and with the knowledge of Prince-Bishop Simon Rudnicki took from there a number of letters and documents in order to publish them, which he never did.

"Following his death, his entire collection was lost"; thus "Copernicus' unpublished work probably suffered the greatest damage at the hands of Johannes Broscius.

"[9] Brożek wrote a biography of Stanislaw Grzepski, a sixteenth-century Polish mathematician and philologist.

As was common among scholars in his era, he published his works under a Latinized version of his name, Johannes Broscius.