In 1708 Becker took over the pharmacy in Købmagergade after his father. He was appointed to field pharmacist ("feltapoteker") in 1709 and accompanied the army to first Scania and later Pommeria. He was present with his field pharmacy at the Battle of Gadebusch in 1712. Later that same year he was appointed to royal court pharmacist. His pharmacy in Købmagergade was completely destroyed in the Copenhagen Fire of 1728 but reopened in a new building in 1737. He was also engaged in large-scale trade with other goods. He was appointed to "Kammerassessors" in 1749,