The 83-year-old, who began reporting on the Magpies in 1959 at the Nottingham Evening News and Football News before making his BBC Radio Nottingham bow in 1968, will continue as the club's correspondant on the station.
In an announcement on the BBC website, Slater said: "I have some personal news for you.
"I've been commentating on Notts County matches for nearly 50 years and I have made the decision that the time has come to step back from those duties.
"But next season I will still be around and I will still be heard on BBC Radio Nottingham - not as frequently but definitely from time to time, and in fact quite regularly, and I hope that you'll join us then. Thank you."
His last commentary for BBC Radio Nottingham will be the Magpies' trip to Newport County on May 6, almost 50 years after he was first heard on the airwaves.
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