The experimental facility and procedure are described for investigatio
n of the stability of interface in the liquid-vapor system. The interf
ace is the surface of a bubble formed in the volume of a thermal, wher
e the liquid is locally superheated. The liquid under investigation is
n-heptane. The range of liquid superheating in the experiments is 100
-200 degrees C. The diagram of characteristic states of interface is t
reated. A model of transition to unstable state is proposed, based on
the Landau instability mechanism.