Hassan Omar Juma was charged with breaking into the Studio City, Los Angeles home of the actor and his wife Idina Menzel on Tuesday (29Jan13).
The 20 year old has pleaded not guilty to one felony count of first-degree burglary with a person present in a Van Nuys court.
Diggs encountered the intruder in his garage after arriving home from the SAG Awards ceremony and told police Juma was "looking for things to take".
The intruder has been in custody since his arrest on Sunday night. Juma is due back in court on 8 February (13).
He faces six years behind bars if convicted.