Inter stunned Barcelona to win the first-leg in extra-time 4-3 on Wednesday night to reach the final 7-6 on aggregate.
Marotta said in the mixed zone afterwards: "It was an epic match between two great teams.
"We are happy to have reached this milestone, which must be credited to the coach, the players and this splendid crowd that supported us almost physically. We are honoured to be able to play the final on 31 May in Monaco because we deserved it."
Asked if the passion shown on the night was the result of Inzaghi's work, Marotta also said: "Certainly. Simone Inzaghi is the centre of this model, supported by the board, by a new ownership that is always present, even if silently.
"It is a victory for everyone, but the greatest architect of this victory is certainly the coach."
"Best night of my career"
He continued, "Beyond all expectations I would say no. This team started to have awareness when they played the final in Istanbul. It is a group that has been together for four years, it has acquired great awareness and great harmony well coordinated by the coach.
"We are among the greats and we are with great merit and with great determination. It was what we wanted and we achieved the objective."
Asked if this was the best match of his career, Marotta added: "From an emotional point of view, definitely yes, also from an adrenaline point of view. It was an advert for all of world football".