Z Andromeda is considered as the prototype of the symbiotic class. This system behaves essentially as the nearly uncontamined nucleus of a young planetary nebula. The parameters of its hot component (R=0,07 R 0, T > 105 K) show that it lies close to the CSPN in the HR diagram (see Fernández–Castro et al. 1988). During the IUE lifetime (1978 onward), Z And experienced a phase of quiescence followed by an active phase which, starting in April 1984, lasted until about July 1986. Since then the star is recovering its quiescent appearance.