It is the best way to protect some area in vacuum from the influence of external electric field.
As we have proved earlier that the electric field inside a conductor is zero. So to protect some fragile materials from the influence of external electric field, we surround them with hollow conductors. The other nice name of hollow conductors is Faraday Cages. No earthling is required in these, not even in case of thunderstorm. So it is advised not to come out of your car in case of heavy thunderstorm and lightning. Car has a metallic body .So no charge or electric field will harm you inside your car. So, our car will act as a ‘Faraday Cage’ or you can say that a hollow conductor. So due to the phenomenon of Electrostatic shielding we will remain safe, instead of standing under a tree or any other thing.
Note: It is not necessary that hollow conductors must be used. An earthed conductor can also help us to protect against electric field.
In the above figure when the conductor was not earthed then the electric field applied on conductor AB due to charge C is shown.
But in the below figure when the conductor AB is earthed then the Electric field becomes unable to cross the conductor.
This technique of electrostatic shielding is applied basically in designing the cables for television.
