Unable to depart before March 1942 due to reconstruction delays, Michel moved under heavy escort to a port in occupied France, sailing on 20 March 1942 for the South Atlantic..
Michel first sank the British tanker Patelle 7,469 tons on 19 April. On 22nd her small torpedo boat Esau sank the US tanker Connecticut (8,684 GRT) but on 1 May an attack on the faster British freighter Menelaus failed. After its warning the Royal Navy sent out the cruiser HMS Shropshire and two AMCs, but Michel sank the Norse freighter Kattegat (4,245 GRT) on 20 May.
LS 4 Esau discovered the struggling US Liberty ship SS George Clymer (6,800ï GRT) and scored two torpedo hits but the freighter refused to go down. The nearby British AMC Alcantara dashed forward and rescued the crew but the ship had to be abandoned. The Germans retreated when the British ship came in sight but nevertheless both British and US never saw a ship and thought the George Clymer was attacked by a submarine.
Various other successes followed, as Michel operated in the South Atlantic and Indian oceans. After a successful cruise of eleven and a half months, Michel arrived in Japan in March 1943, having sunk 15 allied ships, totalling 99,000 tons (GRT).
After refit, Michel sailed from Yokohama on 21 May 1943, cruising the west coast of Australia, and crossing the Pacific Ocean to the coast of South America. Michel encountered and sank 3 ships in a 5 month period, before returning to Japan.
On her return to Japan, just 50 miles (80 km) out from port, and not zigzagging, Michel was sighted by US submarine Tarpon, which attacked in one of the few instances of American submarines tackling a German vessel during WWII. Hit by three torpedoes. Michel sank, with 290 of her crew, including her captain. The survivors, 116 in total, were able to reach Japan after a three day journey in open boats.