The school last week suspended William L. Merrill and barred him from the campus in Mount Pleasant. CMU said its information technology employees found "inappropriate material" on Merrill's computer Nov. 5, and it suspended him that day.
Merrill submitted his resignation Monday.
Isabella County prosecutors charged Merrill last week with distributing child pornography, possessing child pornography and using a computer to commit a crime. He was also charged with possession of a switchblade.