Thomas Schaaf has described his time at Werder Bremen as "extraordinary".
The German club announced on Wednesday that the 52-year-old has stepped down from his role as coach of the team.
"I had an extraordinary time, connected with several positive experiences and great successes," said Schaaf.
"I want to thank everyone who has supported and accompanied me throughout those years. I wish Werder Bremen a successful future."
Schaaf had been the Bremen coach since 1999.