Career
He plays in the role of right wing. Semioli, a Piedmontese who made his professional debut playing for Torino Calcio in 1998-1999. He then signed by Internazionale in a co-ownership deal for 5.5 billion lire as part of Fabio Galante transfer, along with Riccardo Fissore.
He spent seasons on loan to Salernitana, Ternana and Vicenza and loan back to Torino.
Chievo
In June 2003 Internazionale bought the remain half from Torino, and then joint-owned with A.C. (before Christ) ChievoVerona in July for €1.05 million, as part of the loan fee of Luciano. Chievo got full ownership in June 2005 for €500,000 as part of Júlio César"s deal.
He became one of the most representative players for Chievo, and was one of the main protagonists of the very impressive 2005-2006 season contributing 2 goals and 12 assists. One of the top assisters that season.
Fiorentina
In July 2007 Semioli signed for American Car and Foundry Fiorentina for a fee of €7.3million on a four-year contract.
In the 2008-2009 season Semioli was widely believed to be on his way out because of the tactic change and the arrival of players such as Stevan Jovetic. 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. Sampdoria
Following the arrival of Marco Marchionni to Fiorentina, in July 2009, for €4.5 million, it was confirmed that Semioli was transferred to Sampdoria as a four-year deal, for €4 million fee in August, rejoining his former coach at Chievo, Luigi Delneri.
Franco scored his first goal 13 February with a header against his former team Fiorentina which gave Bluecerchiati the lead.
Vicenza
After three years at Sampdoria, Semioli was transferred to former club Vicenza in a deal that included Sampdoria team-mates Marco Padalino and Zsolt Laczkó moving in the same direction, all for free. He capped for Italy U18 team at 1999 Union of European Football Associations European Under-18 Football Championship, lost to Portugal U18 at the final.
In the 2006 Fédération internationale de football association World Cup he was one of the four backup players for the 23-men main squad to step in for any possible injuries. However he was never called up and thus never received a winners medal.
On 16 August 2006, Semioli made his Italy national team debut against Croatia.
Semioli was recalled to the Italy squad for the final Euro 2008 qualifier with Scotland.