Last night's 1-1 draw with Jagiellonia saw Betis win their quarterfinal 3-1 on aggregate. Betis now reach the final four of a European competition for the first time in their history.
Pellegrini said, "I'm very happy to be in the semifinals. Our goal was to get as high as possible. Despite all the criticism at the start of the competition, we've taken it step by step and we're now in the semi-finals, the first time the club has done so, and we're all very happy.
"Now it's time to fight it out with Fiorentina and try to get to the final.
"We were a mature team, although in the first half we may have been playing with the 2-0 lead in our heads, but in the second half we took the initiative and they didn't get close to our goal until that mistake we made. I'm happy for the team and the fans."
"We're all excited"
On his team's achievement, Pellegrini was circumspect: "I don't process it much, I'm not worried about praise or criticism. You look to the coach when something happens and I think rightly so.
"I'm very happy with what we've done all year, we're in a Europa League position and in the semi-finals, and we want to reawaken our ambition to reach another level that wasn't initially budgeted for. The team is getting stronger. We want to win this tournament and reach Europe for the league."
On being now closer to a final, he added: "We're all excited to achieve something that hasn't been done before. We want to reach the top of the table. We have a tough opponent in the semifinals, and we can't be satisfied with what we did. Despite the criticism at the beginning, as I said, we handled it the right way."