The Azzurri reached the quarter-finals by extending their unbeaten run to a national record 31 matches with a tense 2-1 victory over Austria after extra time at Wembley.
Belgium dethroned holders Portugal to set up a showdown with Italy in Munich on Friday, Thorgan Hazard scoring the only goal.
Mancini's side has won 12 consecutive matches, while the Red Devils have gone 13 without defeat ahead of a blockbuster battle in Bavaria.
Conte believes Italy must find a way to keep Lukaku quiet, with the striker having fired Conte's Inter side to Serie A glory with 24 goals last season and struck three times in four Euro 2020 games.
But the former Italy boss thinks the Azzurri can delivier a knockout blow to Belgium, who have injury concerns over midfield maestro Kevin De Bruyne and captain Eden Hazard.
Conte, who left Inter at the end of the 2020-2021 season, said: "As well as the psychological aspect and the attitude: that indispensable mix of grit, concentration, desire to help, the ability to suffer and not give up.
"Each player must put themselves at the service of the group. There are three qualities that differentiate top athletes from normal athletes in modern football: strength, speed and endurance.
"I'm not even talking about the technical qualities that I take for granted. To all this, which is the basis for achieving important results, our national team has shown that it knows how to add its own expression and an idea of the game that other teams have shown less, relying more on important individuals, capable of deciding a game on their own or almost.
"This is what I have also seen some great national teams do, given as favourites. Our next opponent Belgium is a strong team individually and collectively.
"Lukaku is a force of nature, he works alone, but I discover hot water in saying that the presence or absence of De Bruyne and Hazard on Friday can change the balance.
"I have a lot of respect for the coach [Roberto] Martinez for the work he has done in recent ears, but the performance against Portugal did not fully convince me both in the attacking phase and in the defensive phase.
"But Mancini does not need advice, on a tactical level the Italian technicians know how to prepare the game like few others, Roberto [Mancini] will field a team that will be able to manage every situation."