Armero is a director and screenwriter who studied philosophy. He started to work on film in the 1990’s. He directed El columpio (1993), which won the Spanish film award Goya for best short feature. He made his feature film debut with the romantic comedy Todo es mentira (1994). In the next few years he directed five more films: drama Brujas (1996) starring Penélope Cruz, comedy Nada en la nevera (1998), thriller El arte de morir (2000), romantic comedy El juego de la verdad (2004) and the sports comedy Blinkers (Salir pitando, 2007). None of these films were a huge success and he continued his career as director of TV series. His first feature film after seven years is the comedy Sidetracked (Las ovejas no pierden el tren, 2014).