The fire started in the CGL Inc. building at 2255 East Palmdale Boulevard around 4 a.m.
Firefighters had the fire contained by 6 a.m. after dousing the flames from an adjacent empty parking lot. About 300 firefighters battled the blaze. Personnel from the L.A. county and city fire departments responded, as well as from the L.A. County Sheriff's Dept.
The building was believed to be vacant. No injuries were reported.
Traffic on Palmdale Boulevard was not affected.
The cause of the fire was under investigation.