[1] In June 2003 Internazionale bought the remain half from Torino,[4] and then joint-owned with Chievo in July for €1.05 million, as part of the loan fee of Luciano.

However, after season ending injuries to Adrian Mutu and Mario Santana, Semioli found his way back onto the first team, and was a valuable asset to Gilardino, providing him with many crosses and being a terror on the wings.

[16][17] Semioli represented the Italy Under-18 team at the 1999 UEFA European Under-18 Football Championship, where they reached the final, only to lose to the Portugal Under-18 side.

[18][19] In the 2006 FIFA World Cup he was one of the four backup players for the 23-men main squad chosen by manager Marcello Lippi to step in for any possible injuries.

On 16 August 2006, Semioli made his Italy national team senior debut in a 2–0 friendly defeat against Croatia, in Livorno, under Roberto Donadoni.

[25] After retirement as a professional footballer, Semioli obtained the UEFA A Licence, which made him eligible to start his career as a head coach in Lega Pro clubs.