The veteran has earned a new 12-month extension to 2026 this week.
He told Barca's website: "Both my family and I are very happy to continue for another year at this great club, which has fully trusted us from the very first minute.
"We are happy to continue for another year and to be able to continue fighting to win many more titles. It is a pleasure to be at Barcelona , the best team in the world.
"I knew it would be difficult to get here and play... Gaining the trust to renew for another year was even more difficult. It was a major challenge, and I took it that way. Through hard work and suffering, I achieved it. It's a tremendous joy to share the dressing room with these people. It's great to be here. We hope to continue doing well like this."
Martinez, 33, also said: "I'm fine, eager for the matches to end, which are difficult but exciting. It's an exciting year. It's in our hands. We're doing very well, and if we maintain this level, we'll have a chance of winning many more titles, and we hope that's the case."