During the ten years 1593-1603 that van Roomen spent in Würzburg he supervised the dissertations of twenty students which were printed by the local printer Georgius Fleischmann. Most treat medical or anatomical subjects, but there is one on astronomy and one on meteorology. From 1596 to 1603 he was also "mathematician" of the chapter in Würzburg, his main duty being to annually draw up the calendar. It appears that his wife Anna died during these years; they had no children. In 1603 van Roomen gave up his duties as professor at Würzburg, requesting permission from Prince Bishop Julius to travel to Leuven on 19 March 1603. From 1603 to 1610 he lived frequently in both Leuven and Würzburg although he did not officially resign his Würzburg professorship until 1607. He was ordained a priest in Leuven in 1604 or 1605. He was made a canon at the church of Saint John of Würzburg on 1 October 1605 but, due to the many travels he undertook, he seems to have failed to fulfil all his obligations as a canon and he was reprimanded in November 1609. In September 1610 he requested that he be given leave from his duties as a canon for two years, but that he might continue to be paid. His request for continued payment was refused. The reason for this request was that van Roomen had been invited to the Zamoyski Academy in Zamosc, Poland. This academy had been founded in 1594 by the Polish Crown Chancellor Jan Zamoyski (1542-1605).