How can I find the nth derivative of the function $f(x)=e^{-1/x^2} \text{, if } x \neq 0 \text{ and } 0 \text{, if } x=0$.

Question

There is a function

$f(x):= \begin{cases} e^{-1/x^2}, & \text{if $x \neq 0$} \\ 0, & \text{if $x=0$} \end{cases} $.

That function's $n$-th derivative is $0$ : $f^{(n)}(0) = 0$.
How to derive that?