The Brazil-born Spain striker Costa has done much to please Conte this season and tops the Premier League scoring charts with nine goals from 11 games.
It was only a month ago, however, that he clashed publicly with the Italian during last month's win over Leicester City but relations between Costa and his coach have clearly improved.
“He's an example for all,” Conte told British media.
“If he continues to score, I'll be very happy. But I'll be happier to see this commitment, this work rate during training and in games.
“It's fantastic, I think, that Diego is improving a lot in a lot of aspects. For me, now, Diego is one of the best strikers in the world.
“He must continue that, working in this way, with his commitment and work rate.”
Chelsea, who next play Middlesbrough on Sunday, have risen to second in the league on the back of a five match winning-streak in which they have scored 16 goals and conceding none.
Original source: Conte lauds Costa as an ‘example for all’