The Pole says confidence is sky high after last week's win at Chelsea.
"The spirit within the team is very positive and we are very confident going into every single game," Szczesny told arsenal.com. "We feel like we have what it takes to win every game and I am sure we can keep it going.
"I would have preferred a 1-0 win. But if you told me beforehand that we would get four points from the two games against Marseille and not concede I would have taken it. I'm pleased with the result.
"It's always difficult in the Champions League because you have to play against top, top opponents but I am confident we can keep our form going and get the results to qualify for the next stage."