Eyebrows were raised in Italy when former youth team coach Stramaccioni was handed the role on a permanent basis after originally taking the reins as a caretaker after Claudio Ranieri was sacked.
However, Moratti insists that the 36-year-old deserves his chance to prove the critics wrong.
Moratti told Corriere dello Sport: "I feel it is right that he has the way and the time to be able to organise his job.
"We believe in him, we want him to build the future of Inter and this contract, in my opinion, is the right way to give him a sense of confidence from our part.
"It's true that he doesn't have much experience working with first teams, but from day one he came across as a talented coach."
Stramaccioni has been handed a contract for three years.