World football needs a "change of culture" in the wake of Sepp Blatter's resignation, FAI chief executive John Delaney said.
Mr Delaney, who had become an outspoken critic of the 79-year-old in recent days, said he was "delighted" Blatter had announced he was stepping down.
But he added that more change is now needed to end the "culture of corruption and bribery" that has allegedly developed during Blatter's 17-year tenure.
Blatter - who has denied any wrongdoing - had responded to last week's arrest of a number of FIFA officials by saying he welcomed the investigation.
Mr Delaney last night described Blatter's shock resignation as "a good day for world football".
He said he was not surprised by the decision despite Blatter winning re-election last week.
"There was momentum against him, be it from sponsors, be it the FBI, be it the British government, be it from within football where nearly 40pc of the organisation had the bravery to vote against him," he said on RTE news.
He added that world football now needs "to move on".
"We can see that the culture of FIFA was one of corruption, one of bribery, nothing to do with the beautiful game, more to do with, as I described it last week, a Mafia movie rather than football."
He added that it was time for a president "who really believes in change", and said FIFA should follow the example set by the International Olympic Committee which was previously dogged by similar scandals.
"I'm delighted today that Blatter has stepped down. I'm just hopeful that we can carry that change through now," he said.
"It's a once-off opportunity. It's a great opportunity to get world football back on to the front pages for the right reasons, not all the wrong reasons."