The 21-year-old central defender was signed from Espanyol in the close-season and has become an important part of Swansea's defence in the UEFA Europa League, making nine of his 14 appearances in the competition.
And he said the opportunity to play regular football was already paying dividends for his development.
"Being part of this team is very enjoyable for me," he told the club's official website. "The style is perfect and I think I am improving with every game I play.
"Playing in the Premier League and also the Europa League has been a dream for me.
"I've learned so much not only in the games but on the training pitch too. Watching (fellow centre-backs) Ashley Williams and Chico Flores is an education for me, and also listening to the advice of the coaches too has really helped me.
"Playing against the different styles and tactics of opposition players and teams in the Premier League and on the continent has been massive in my development here."
Amat has started Swansea's last two matches but may find himself back on the substitutes bench when they face Everton on Sunday, following Chico's return from suspension.
