Emery signed goalkeeper Bernd Leno from Bayer Leverkusen in the summer for £22m, but Cech retained his starting role for the new manager’s first league match in charge of Arsenal.
Cech, 36, insisted he is comfortable with a new style of play under Emery which places an emphasis on playing out from the back.
He attempted more passes in the 2-0 defeat to Manchester City than in any Premier League game he played last season under Arsene Wenger, Emery’s predecessor, but lost possession 11 times.
“I am very happy with his performance,” Emery said ahead of Arsenal’s next Premier League fixture, which sees them play Chelsea at Stamford Bridge on Saturday.
“I think he has experience, quality, capacity like a first goalkeeper with us – and also Bernd Leno.
Former Arsenal goalkeeper Jens Lehmann has his say on the battle between Petr Cech and Bernd Leno
“They are two important goalkeepers for us. Different qualities but for us, like we want to play, the two goalkeepers can play.
“Saturday the decision is easy, Petr Cech will continue to start the match, I believe in him. If he starts bad, I believe in him also.”
Ainsley Maitland-Niles was deployed at left-back against Manchester City but has fractured his fibula and will be out for up to eight weeks.
Emery confirmed Nacho Monreal has been training all week and is an option to return to the side against Chelsea, while right-back Stephan Lichtsteiner could also be switched to the opposite flank.
The Arsenal boss was criticised for his attempts to play from the back against Man City’s high-press style.
But asked on a timescale for when ‘the Unai Emery way’ will be embedded, he said: “You need more time to completely look how you want.”
He added: “The first game give us more information for things to improve.
“We need to continue in our way, to make this difference in the next match and in the future.
“For me it’s most important the players know positive things we did, and also the things we need to improve.”