Szczesny made his 100th Premier League appearance in last weekend's 2-0 win over Fulham and has been a key figure in helping Arsenal to lead the table.
He was dropped for a few weeks towards the end of last season, but Wenger has been delighted with the way the 23-year-old has continued to improve.
"Certainly a part of his improvement is mental because he's more mature," Wenger told Arsenal Player.
"His decision-making is cleaner, sharper, quicker. He was always a very talented boy but because he's intelligent he learns quickly from experience.
"I'm happy that I always gave him the confidence because he's developing very well into a very strong goalkeeper and today certainly nobody would question that he's one of the top five goalkeepers in the Premier League."
Arsenal boast the best defensive record in the Premier League after conceding just 19 goals in 22 games and only six of those goals have come at the Emirates Stadium.
Wenger added: "That defensive solidity of course is the basic work you have to do to be efficient at home.
"Maybe what is even more important is to have that solidarity at home because it gives you time to fatigue your opponent, time to stretch them, time to dominate them and get the game completely in their own half. The longer that lasts the more you have chances to score."