The famous 80,000-capacity stadium, home of both Milan clubs, was opened in 1926 and later named in honour of Giuseppe Meazza.
Berlusconi said it was time for her club to move forward, though, but is unsure whether it will be possible.
"San Siro is a marvellous stadium, where the history and the apex of Milan and Inter was reached, but today it isn't enough anymore," Berlusconi told Rai 1.
"Stadiums have to provide different services and infrastructure to be open seven days a week, not just on match day.
"Now in Italy there are so many difficulties. There's little economic support from the state, the region or the council."
Berlusconi said the nation's football was "a microcosm of what is happening in the country in general, that of a country that does not want to renew itself."