Monreal, who joined the Gunners in January 2013, has been in impressive form this season and has featured in all of the club's Barclays Premier League matches
The 29-year old defender said : "I'm really happy because my intention was to keep playing for Arsenal
I feel really good playing here."
Monreal, who arrived from Malaga for a reported Â£10million, has won successive FA Cups with Arsene Wenger's side and usurped Kieran Gibbs from the left-back spot
The Spaniard added: "I have a good relationship with my team-mates and we keep improving year after year
I wanted to stay here and I could extend my contract
I would like to play here for many more years.
"The trust of the Arsenal fans is really important for us because they are helping us in every moment as we are fighting to win the Premier League
"I met the boss three years ago and I have a really good relationship with him and I'm really happy with him
For these reasons I extended my contract
"I'm very happy with my performances this season
At the beginning it was difficult because I was a new signing and I didn't speak English
"But now I feel more comfortable with my team-mates and with everything in general so that has helped me to play better because I have more confidence in myself."
Arsenal manager Wenger hailed Monreal's impact following his arrival from La Liga three years ago
"He is a very important player at the club because he can play left-back and centre back," said Wenger, whose Arsenal side sit at the top of the Premier League
"He has the consistency in his performances that is requested at the top level
"Overall, his attitude has been absolutely fantastic on a daily basis since he arrived here
He's 100 per cent committed and I think as well he has always improved since he has arrived and has shown that in many big games as well
"He's calm, focused and dedicated
He's well-accepted and loved by his partners
He has the modest approach of a player who wants to give his best to the team
Everybody senses that and that's why I think it's important for the club to have that stability
"Everyone in the Premier League would say that he has become a very strong player
Arsenal are gifted at the moment, I must say, with two top-class left backs
We have many young players
They need to be surrounded by experienced players, especially at the back
"We now have experience at the back
Nacho is part of that - he's a good example for the young players and we have a good bunch of young players."
Source : PA