Carwyn Jones' comments came as he visited the region, including Caernarfon Castle, as part of Armistice Day commemorations.
At the site of the new school at Maesgeirchen in Bangor, Mr Jones met pupils who have been involved in designing their new classrooms.
The school is due to open in September 2017.
"It's been a pleasure to be here in Maesgeirchen today to see this fantastic development which will be of real benefit for the pupils, teachers and parents," said Mr Jones.
"It's not only the pupils and teachers who'll benefit from this new development, but the wider community will too as this is a major construction scheme creating employment and providing opportunities for local suppliers."
The new Ysgol Glancegin will serve what is Wales' third largest housing estate, with a population of 4,000.
A new £5.1m Gwynedd school will deliver the "best possible start in life", Wales' First Minister has said.