  A nonthermal particle acceleration mechanism involving the interaction of a
charged particle with multiple magnetic islands is proposed. The original Fermi
acceleration model, which assumes randomly distributed magnetic clouds moving
at random velocity $V_c$ in the interstellar medium, is known to be of
second-order acceleration of $O(V_c/c)^2$ owing to the combination of head-on
and head-tail collisions. In this letter, we reconsider the original Fermi
model by introducing multiple magnetic islands during reconnect ion instead of
magnetic clouds. We discuss that the energetic particles have a tendency to be
distributed outside the magnetic islands, and they mainly interact with
reconnection outflow jets. As a result, the acceleration efficiency becomes
first-order of $O(V_A/c)$, where $V_A$ and $c$ are the Alfv\'en velocity and
the speed of light, respectively.
