On 1 September of 1969 began work Wyższa Szkoła Nauczycielska w Siedlcach (Teaching School in Siedlce) and the structure of the Faculty of Mathematics and Natural Sciences. It gave a beginning to the present Faculty of Sciences. Its first Dean was Asst. PhD Alina Suszko-Purzycka, a woman with a great personality and inexhaustible energy directly, which is a large part of his life devoted to the fact that in the county in the eastern Polish university created to instill in this environment, academic tradition, academic way of thinking. The effects of the present work shows the potential of teaching and scientific research department .
The seat of the faculty has become old, dating from 1919 building of the former Seminary Street 3 Maja 54, totally unsuited for teaching laboratory. However, in a relatively short period of time has been extended and modernized to meet the needs of teaching and research staff and students of chemistry, and then after the next expansion, carried out in the early years of the twenty-first century could also be used by students and staff of mathematics and computer science courses.
The Faculty of Science has three institutes: the Institute of Chemistry, Institute of Mathematics and Physics and the Institute of Computer Science. They cover quite a large complex of buildings in which there are three modern lecture halls for 450 seats in total, several laboratories and computer rooms. Since 1998, the Council of the Faculty of Science has the power to confer the degree of Doctor of chemical sciences in chemistry.