The 21-year-old, who has had six loan spells during his time at the West London club, came on for Michy Batshuayi in the 80th minute of the Blues' 4-2 EFL Cup third round win over Leicester City on Tuesday night.
Of the debutant, Conte said: "I want to have the whole squad, not only 11, 12, or 13 players, and create good competition.
"For example, today I'm pleased for Chalobah. It's his first game.
"He is a product of the Academy and I am very happy for him. I want to show if someone deserves, he plays."