The newborn baby boy miraculously survived the seven-foot fall but had stopped breathing and was suffering from hypothermia when he was found.
Medics managed to resuscitate the newborn who is now said to be in a ‘serious condition’ in hospital.
The mother was arrested on suspicion of attempting to kill her child, police in eastern Madrid said.
The unnamed 35-year-old, who lives with her parents but kept the pregnancy a secret from them, cut the umbilical chord herself after giving birth in the early hours of the morning.
She then wrapped her newborn baby up in a pair of jeans and threw the bundle out of kitchen window on to an interior patio seven-feet below.
Police said in a statement: ‘The woman wrapped the baby in a pair of jeans and threw it out of the kitchen window into an interior courtyard.’
But when the woman started to bleed heavily soon afterwards, she had to ask her parents to take her hospital.
It was only a few hours later that her mother, the baby’s grandmother, went into the kitchen and spotted the baby on the patio.
Police added: ‘Later, at about 8.30am, the grandmother of the newborn went into the kitchen and, looking out of the window, saw a baby in the patio.
‘She ran out to pick it up and alerted emergency services.’
Two police officers who attended the scene wrapped the baby in blankets to try and keep him alive until paramedics arrived.
At one point the child stopped breathing but medics managed to revive him.
