The Frenchman, who resigned in May after being banned for from the sport for four years for ethics violations, was given a round of applause by the delegates but did not get a standing ovation.
"Thank you. Thank you for these nine years. I think we did a great job... Friends of football, farewell," said Platini, who was first elected in 2007, at the end of his seven-minute speech.
His replacement was to be elected immediately afterwards with Slovenia's Aleksander Ceferin and Dutchman Michael van Praag as the two candidates.
Despite Platini's ban, FIFA's ethics committee said an exception had been made for the event as a "gesture of humanity."
"It's very emotional for me to be here but I'm also delighted to be here because this will be my last speech to a UEFA Congress," Platini began.
"You are going to continue this wonderful mission without me for reasons I don't want to go into today.
"I have a clear conscience, I am certain not to have made any mistake and will continue to fight this in the courts."
One of the finest players of his generation who went on to become a powerful sporting official, Platini was suspended over his dealings with fallen world football chief Sepp Blatter during the scandal which shook the sport's global governing body last year.
Platini was banished along with Blatter over a payment of two million Swiss francs (1.57 million pounds) made to the Frenchman by FIFA with Blatter's approval in 2011 for work done a decade earlier.
Platini said that football was "a game rather than a product, a sport rather than a market, a show not a business."
"There isn't one football for large nations and one for small nations, there is a single football, a single sport, it doesn't belong to FIFA or UEFA, it belongs to the whole world," he said.
"That is why I wanted to come today to say thank you and, friends of football, farewell."
(Editing by Amlan Chakraborty)
