The Czech keeper ended a trophy-laden 11-year association with Chelsea on Monday after finally completing a long-anticipated move to their London neighbours
Press Association Sport understands Cech has been signed for Â£10million and has penned a four-year deal
The 33-year-old found himself behind Thibaut Courtois in the pecking order at Stamford Bridge last season and seized the chance of first-team football at another Premier League title challenger
Arsenal have struggled to find a consistent keeper ever since the departure of Jens Lehmann in 2008, but Seaman reckons Cech's arrival will bring long-term stability
''Chelsea's loss could, and likely will, be Arsenal's gain
In my opinion this signing could genuinely be the difference between who will come first and who will come second next season,'' he said on BreatheSport
Cech won 13 trophies at Stamford Bridge, including four Premier League titles and the 2012/13 Champions League, but insists he remains as hungry as ever
He told Arsenal's YouTube channel: '' 'I spoke to the manager Arsene Wenger and it was a big difference as I am hungry as ever and I have the same commitment and motivation to win trophies as I did 10 years ago or as a kid.''
Wojciech Szczesny, whose place in the Arsenal team Cech is set to take, welcomed the new signing with a post on his Facebook page
''Petr Cech, welcome to Arsenal FC! Delighted to have a chance to learn from one of the best GK's in the world!'' the Pole wrote
Cech bade a heart-felt farewell to Chelsea supporters in an open letter on his Twitter page
''I thought this would never happen but it is time for me to say goodbye to Chelsea Football Club,'' he wrote
"The club I have lived every single minute for since joining in July 2004, the club in which I thought I'd hang my gloves and boots one day and finish my career
But life doesn't always turn out the way you think it will
''Last summer, things changed and I understood I was no longer the first choice keeper but I felt it was not the right time for me to go
''During the season it became clear that my situation would not improve and as I know I am not at the stage of my career where I want to be on the bench, I made my decision to move on and look for new challenges.''
Cech expressed his gratitude towards Chelsea owner Roman Abramovich for allowing him to remain in England, even though it meant selling him to a potential title rival this season
He also thanked the Chelsea fans, saying: ''I did everything for you and you gave me your love back
I'll never forget it
It will stay with me forever."
Source : PA