Police said that the “alert” worker found the girl shortly before 6.30am at the address Værebrovej 90 in Bagsværd, a suburb located roughly 12 kilometres to the northwest of Copenhagen.
TV2 reported that neighbours in the area reported hearing “heart-wrenching screams”.
The baby was reportedly thrown down the building's internal rubbish chute and landed in a waste container. A rubbish collector found the baby when he went to empty the container.
The girl, who weighs around three kilos, was taken to Copenhagen's Rigshospitalet.
“The girl is alive and doing well under the circumstances,” a short police statement said.
Copenhagen Vestegn Police are asking anyone with potential information to contact them on 43861448.
According to news agency Ritzau, the incident marks the 13th time that a newborn was abandoned in Denmark since 2004. In five of those incidents, the baby was found dead.
Following the August 2015 discovery of a baby between two rubbish containers in the Copenhagen suburb of Ballerup, the National Council for Children (Børnerådet) called on Denmark to introduce legislation allowing for infant safe havens, also known as baby hatches.