The Gunners manager has backed the France international to find the back of the net when Rafael Benitez's Serie A side come to North London on Tuesday
The France international has been in lethal form for the Gunners this season, scoring four goals in six Premier League games, and Wenger believes there is still more to come from the 27-year-old.
“I think he will improve and be better in all aspects of his game. At 27, you always think the best years are coming for him now,” Wenger told reporters.
"He is already one of the leading strikers in Europe. I am hoping he can make his mark in the Champions League. If the team performance is good, then I am sure that he will."
Giroud joined Arsenal last summer from Montpellier – a transition which Wenger believes was difficult for the Frenchman.
However, team-mate Bacary Sagna believes the striker has now adapted to life at Arsenal and feels Giroud has played a vital part in the Gunners' strong start to the season.
“If we are on top of the league today, it is because [Giroud] made a lot of improvement and he is an important part of the team,” said Sagna.
“We need to give him time and I think he will improve even more, and be more decisive.
“He questions himself every day, wants to learn and improve, even on his English which helps a lot.”