Template decomposition upon calcination of EMO and EMT zeolites has been studied using thermal analysis techniques. For both samples, desorption of water occurs below 200 degrees C and template decomposition at 250-450 degrees C. It is concluded that the template decomposition in EMO and EMT zeolites is relatively slow and is not structure-sensitive; it is accompanied by rapid desorption of the products, XRD studies on the calcined samples show no decrease in their crystallinity. However, both NMR- and IR-spectroscopy indicate partial distortion of the framework and formation of Lewis acid sites. A non-destructive activation of zeolites prepared with organic templates is proposed.