"Twenty-four is OK... I think it's OK. Eight good teams to add. It's not a problem of quality," Platini told reporters on Monday, looking ahead to France 2016 after giving a glowing assessment of the ongoing tournament in Poland and Ukraine.
Euro 2012 has provided plenty of goals and entertainment in the 22 matches to date and approaching the end of the group stage is yet to feature a goalless draw.
"We can have eight more teams as good as the rest, and also have a fantastic round of 16," added Platini.
"It's very important for the [additional] countries that qualify. It is good for the national associations and their development.
"The sponsors are present because they are proud to participate."
Platini said more teams meant "more games in stadiums which leads to better investment".
"How can we ask to a city like Lviv to build an airport, to build a big stadium, and after three games it is finished for the Euro?"
Three-times European champions Germany have said they have "mixed feelings" over the expansion of the tournament.
