The Hammers reached the semi-finals in remarkable fashion after beating Lyon 3-0 away in the second leg of their quarter-final.
Craig Dawson, Declan Rice and Jarrod Bowen tore through the Ligue 1 side to win 4-1 on aggregate.
Moyes has been hesitant to label his favorites throughout this tournament and still won’t, but the Scot wants his team to believe they can face anyone in this tournament.
West Ham will now face German side Eintracht Frankfurt for a place in the final in Sevilla next month.
“We are not favorites [to win it]but I want the players to think they are,” Moyes said.
“Immensely proud of the players and the performance and probably more, looking back, the performance in the second half of the first leg when we were down to 10 men which felt like a really bad decision.
“The players stayed true, never gave up, scored a goal before we conceded. I don’t think anyone when he asked me questions earlier thought that we we were going to get there tonight.
“It’s huge what we have done in two years. We haven’t won any trophies yet, but we are trying to compete and qualify for European football again, if we can. To get to these final stages, we beat big clubs used to European football.
“You don’t win anything for tonight but it was a great moment for us. Winning 3-0 away in Europe – very good result.