The Gunners head into the European clash against the French club boosted by Saturday's 5-2 trashing of north London rivals Tottenham.
Montpellier, meanwhile, are without a win in their last four matches, and have no chance of making the last 16, bottom of the group with just one point.
Victory for Arsenal on Wednesday night, coupled with a home win for Schalke against Olympiacos, would see them qualified ahead of Matchday Six.
Wenger, though, insists his team must go into Wednesday's encounter with the correct focus if they are to avoid a second successive home European defeat.
"Not for a second would I think the team will be complacent tomorrow [Wednesday] - they will be full of desire to do well and win the game, I am certain of that," he said.
"It is important on the back of the Tottenham game we show another good performance and a resolute attitude, that is at stake for me tomorrow. After, if we produce the quality performance, we will win the game.
"We do it step by step. First of all we want to qualify, then try to top the group, so let us just win the game tomorrow."
Wenger added: "Montpellier had a slow start to the season, but they have rediscovered their balance over the last few months and they played very well against Paris St Germain.
"It should be an open game because a draw is not good for either side."
Arsenal will be desperate avoid a shoot-out for a place in the knockout stages when they travel to Athens, where they were beaten 3-1 last season and also lost in 2009.
Defender Per Mertesacker echoed Wenger's call to deliver the required performance on Wednesday night.
The German said: "We have to get good results now, there is no space for weak games or for another home defeat.
"We are completely concentrated on this game and we have to take this stage as Arsenal have done in [previous] years.
"The group is still open for the teams, and we have to show we can go through and make clear that Arsenal will go to the next round."
German international Mertesacker has come a long way since his first tentative steps into English football after signing from Werder Bremen last summer.
The 6ft 6in centre-half headed in his first Arsenal goal in the 5-2 victory over Tottenham at Emirates Stadium on Saturday.
He said: "I had a very difficult first season with all the settling in and the new things at Arsenal.
"It was quite tough for me, but now I feel much more comfortable with the situation.
"It is much more physical than the Bundesliga so you have to make your mind up about the tackles, about the way you cover your partner, so I set those things up a bit and I feel much better than last season.
"I try to keep on going with that feeling."
Arsenal will be without forward Theo Walcott on Wednesday, the England forward having suffered a shoulder injury against Spurs.
Winger Gervinho, out since October 27 because of an ankle problem, trained this morning, as did full-back Kieran Gibbs, who last featured at West Ham on October 6.
Walcott, 23, has yet to agree new deal at Arsenal, and as such could leave at the end of the season on a free transfer.
Wenger has ruled out selling the forward during the January transfer window should the impasse over negotiations not be resolved.
"There is a risk, yes, but that we are ready to take," said the Gunners boss.
"A successful season is more important for us than this risk that is only a financial risk, apart from the losing the player.
"If we sell him, we lose him anyway.
"I believe that we started the season with this squad and we want to finish the season with this squad.
"What is important is what we achieve together for the season - to do that I just think that Theo is a big part in that."