He was the son of Emil Bertrand Münster (1816–1888), a professor of metallurgy, and Andrea Sophie With (1829–1918).
[1] When he retired as a mine manager in 1918, he was given a government scholarship to continue his research on entomology.
[4] Münster donated an extensive private collection of entomology books to the University of Oslo Library.
He also produced a manuscript of twelve large volumes, in which he summarized all known finds of Norwegian beetle species.
Together with Knut Dahl and Johannes Lid, in 1924 he coauthored the work A Division of Norway into Bio-Geographical Sectional Areas Agreed Upon by Botanists and Zoologists.