To solve the exponential equation \( (10)^x = 0.001 \), we can first rewrite \( 0.001 \) in terms of a power of \( 10 \):
\[ 0.001 = \frac{1}{1000} = \frac{1}{10^3} = 10^{-3} \]
Now, we can rewrite the equation as:
\[ 10^x = 10^{-3} \]
Since the bases are the same, we can set the exponents equal to each other:
\[ x = -3 \]
Thus, the solution to the equation \( (10)^x = 0.001 \) is:
\[ \boxed{-3} \]