Following flight training, Münster was posted to Jagdgeschwader 3 (JG 3—3rd Fighter Wing) in March 1941.

Flying with this wing, he claimed his first aerial victory on 6 July 1941 on the Eastern Front during Operation Barbarossa.

Münster was born on 13 December 1920 in Pohorsch (Pohoř) in the district of Neutitschein (Nový Jičín) within the Sudetenland region of Czechoslovakia, present-day part of Odry in the Czech Republic.

In 1926, Münster attended the Volksschule, a combined primary and lower secondary school, in Hochheim.

[3] Following the German occupation of Czechoslovakia in October 1938, Münster volunteered for military service and joined the Luftwaffe on 7 January 1939.

[3] In July 1940, Münster was transferred to the advanced Flugzeugführerschule C (FFS C—advanced flight school) at Burg bei Magdeburg where he received further theoretical training.

[5] World War II in Europe had begun on Friday, 1 September 1939, when German forces invaded Poland.

Münster completed his fighter pilot training in March 1941 and then flew some missions in Defense of the Reich from Fürth and Zerbst.

[5] The Ergänzungsgruppe was a supplementary training group attached to JG 3 under the command of Major Alfred Müller with 2.

These air elements supported Generalfeldmarschall (Field Marshal) Gerd von Rundstedt's Army Group South, with the objective of capturing Ukraine and its capital Kiev.

At 17:00 on 21 June 1941, the 5th Air Corps, based at Lipsko, briefed the various unit commanders of the upcoming attack.

Gruppe flew its first missions on the Eastern Front shortly before 04:00, flying low attacks against Soviet airfields in the vicinity of Lvov in Ukraine.

[8] In the beginning of July 1941, the front in the vicinity of the northern sector of Army Group South became increasingly fluid.

[5] Following his ninth aerial victory claimed and 86 combat missions flown, Münster was transferred to the Stab (headquarters unit) of II.

Additionally he was credited with five ground victories and the destruction of a locomotive, increasing his number of combat missions flown to 124.

Gruppe was ordered to an airfield at Santo Pietro, approximately 15 kilometers (9.3 miles) northwest of Comiso, Sicily.

[5] Based at Chuhuiv, the Gruppe participated in the Second Battle of Kharkov, the Soviet attempt to retake the city.

In the following days, the Gruppe fought in the Battle of Kalach, supporting the German crossing of the Don.

[18] On 24 July, Münster became an "ace-in-a-day" when he shot down five Il-2 ground-attack aircraft and a Hurricane fighter, taking his total to 30 aerial victories claimed.

[19] From 21 November 1942 to March 1943, Münster was first hospitalized in Troppau, present-day Opava, where he received surgery and then spent some time convalescing.

That day, the Eighth Air Force targeted Bremen and Münster was credited with shooting down a Boeing B-17 Flying Fortress bomber.

[24] On 8 May, Münster was killed in a mid-air collision with a Consolidated B-24 Liberator bomber, possibly from the 445th Bombardment Group.

[25] His Messerschmitt Bf 109 G-6/U4 (Werknummer 441142—factory number) crashed near Wöllersheim, present-day part of Lamspringe, approximately 18 kilometers (11 miles) south-southeast of Hildesheim.

[28] Spick also lists Münster with 95 aerial victories claimed in an unknown number of combat missions.