Cowell, 51, spoke in retaliation to comments that the Rocket Man had earlier made about the acts on the show after he called them 'boring' and 'brain crippling'.
After contestant Rebecca Ferguson's performance, Cowell said: 'Elton John said in the papers... he said that these shows don't produce stars.
'Well Elton if you're not watching, I'm going to send you this tape and you can take back what you said.'
He also spoke to UK newspaper the Sunday Mirror and said: 'The truth is Elton's watching the show every week.
'What he's slightly missing the point on, and you always hear this resentment from bigger artists nowadays... they don't like the fact that a show can make an artist.
'I always say to these people who criticise - why don't you spend some time with new artists. If Elton feels that strongly about it then my message to him is: 'You show me how to do it'.'