Raul leaves the Castilla after six years in the job.
The former Real Madrid captain posted to social media today:
"Today, I informed Real Madrid of my decision to end my time at the Club.
"These have been seven seasons in which I've enjoyed the passion I've had for football since I was a child. I'm sure these years have helped me grow as a professional and as a person.
"I'm grateful to the club of my life for the opportunity it's given me over all these years. And I want to thank all the employees here and everyone at Real Madrid, because they've all given me their support and love and helped me pursue one of the most beautiful jobs in this sport: sharing the experience and knowledge I've acquired with young players to watch them grow as people and as athletes."
A new stage in my life
Raul also said: "I will proudly enjoy the successes achieved by each of the boys I have coached, and they all receive my love and gratitude for everything they have given.
"A new stage in my life as a coach now begins outside of this Club, and I am convinced that one day I will return to what has always been my home.
"Thanks everyone. Hala Madrid!"