The Los Angeles County District Attorney's Office charged Edgar García-Franco with 38 counts of invasion of privacy.
Signal Hill police said they found a camera in an employee-only restroom at the restaurant on East Spring Street on Sunday.
They said the camera was put in a trash can with a hole in the side of it.
Prosecutors said Garcia-Franco secretly recorded eight women and a man between July and August.
Police said there is no evidence that patrons of the restaurant were videotaped.
The 49-year-old pleaded not guilty to the charges, and bail was set at $150,000. He faces a possible maximum sentence of 19 years in jail if convicted as charged.