To find the missing number in the equation \( 33.00 \times x = 0.33 \), we need to isolate \( x \).
First, we can rewrite the equation:
\[ x = \frac{0.33}{33.00} \]
Now, we can perform the division:
\[ x = \frac{0.33}{33} \]
Calculating this gives:
\[ x = 0.01 \]
Therefore, the missing number is:
\[ \boxed{0.01} \]