(-3 \cdot 10^4) \cdot (2\cdot10^{-3}) =

To solve \((-3 \cdot 10^4) \cdot (2 \cdot 10^{-3})\), we can break it down step-by-step.

1. **Multiply the coefficients**:
\[
-3 \cdot 2 = -6
\]

2. **Multiply the powers of 10**:
\[
10^4 \cdot 10^{-3} = 10^{4 + (-3)} = 10^{1} = 10
\]

3. **Combine the results**:
\[
-6 \cdot 10 = -6 \cdot 10^1
\]

Thus, the final result is:
\[
\boxed{-60}
\]