The present invention provides a method and apparatus for non-invasive reduction of excessive fat tissue by externally applying radio frequency (RF) electromagnetic (EM) waves adjusted to specific fat cells absorption frequency and electromagnetic propagation mode. Based on the performed experiments described further, the method and working apparatus has been invented that reduces fat layers without any medication, non-invasively through the intact skin. The invented method and apparatus facilitates the safe fat removal, and may lead to reduction and eradication of obesity and obesity associated diseases.