Hyypia took joint control of the team in April 2012 with Sascha Lewandowski before taking sole charge when the Pole switched to a role in the youth set-up in June last year.
Leverkusen are second in the Bundesliga after claiming 40 points from 19 games so far and face an upcoming UEFA Champions League last-16 tie with Ligue 1 side Paris Saint-Germain, with the first leg taking place on February 18.
And Leno believes Hyypia's calm manner has been key to Leverkusen's success.
"I didn't play with him as a player, but he's doing a great job as a coach," Leno told UEFA.com.
"He can deal with the players. He's great on a human level and he has a clear vision of what he wants to do. He's very precise.
"He is not one to shout and jump around on the sidelines. He conveys his message in a calm manner."
However, Leno knows Leverkusen will need to improve if they are to overcome PSG in the Champions League after conceding nine goals in the two group-stage meetings with defending Premier League champions Manchester United.
"Maybe we were overawed by them (United)," Leno added.
"They also scored at the right times. (Robin) van Persie and (Wayne) Rooney have great skills, but that goes without saying. We made too many individual mistakes and they were clinical."
