From an earlier answer of mine

The surrender agreement in 1945 called for the handover of all war material to local Allied military forces and the immediate status of the war material was determined by the victorious Allies. Some of this war material was designated for immediate use and testing. Captain Eric Brown, one of the RN's chief test pilots and fluent in German, ranged throughout Germany looking for flyable examples of state of the art Luftwaffe aircraft that could be returned to the UK and put through their paces. The Type XXI and Type XIII submarines elicited considerable interest from all of the Allied powers and they became war booty, as did the experimental Walter high test peroxide submarine, which entered into British service as HMS Meteor Meteorite. The French looked to German war material as a means to supplement their own rearmament in the postwar period. The Soviets tended to keep war material that was in working condition to parse out to its allies in Eastern Europe (or allow their allies to retain this material and some of its production, such as Czechoslovakia). This was a way to ease the defense burden on the Soviet occupation in the immediate postwar years while keeping its allies in a subordinate position. But inertia and expediency also played a role as the war material was already there and the Red Army had no need for it.

But the above examples were the exceptions, not the rule. The overwhelming bulk of German war material was scrapped in the immediate postwar years, There was little interest in maintaining or even demilitarizing this equipment as much of it was already in bad shape by April 1945. Aircraft boneyards often had the planes stripped of valuable materials and the planes were simply melted down or thrown into a landfill. The same applied to tanks and other heavy equipment; salvageable engines might be removed and some parts used in reconstruction. The barrel of the La Gleize museum's Tiger II tank is actually a Panther barrel that was recovered from a Belgian barn where it was used as a support beam. The American zone had a structured recycling plan, Gesellschaft zur Erfassung von Rüstungsgut m.b.H. (GER)- later retitled Staatliche Erfassungsgesellschaft für öffentliches Gut m. b. H. (STEG), in which German intermediaries worked to recondition or salvage war material that could be put to civilian use. GER/STEG warehouses worked on items like uniforms and boots and other state materials, including surplus US material. The organization's portfolio also tasked it with separating out components useful to peaceful purposes and handing over other materials for destruction. Corruption within GER/STEG was pretty common as the amount of state-owned material at its disposal was quite vast while the postwar years was one of great dearth. GER/STEG's role in reconstruction is one that is pretty understudied and there is an forthcoming article in War & Society about the agency.

Munitions posed a particular problem for the occupation. Some German munitions could simply be immediately repurposed for the destruction of obstacles and fortifications. But that still left a massive quantity of explosives, including chemical and nerve munitions that were not used during the war, but stockpiled by Germany. The British zone authorities tended to dump mass quantities of munitions into the ocean. The other Allies followed suit by burying them in landfills or dumping in lakes. Although news media reports on unexploded munitions typically stress that the weapons were the byproduct of wartime use, the sheer scale and haphazard nature of postwar disposal operations does not rule out these legacies of the war were the result of peacetime negligence. The decay of these munitions, especially the chemical weapons, has caused some alarm in environmental quarters, as this Spiegel article outlines.

Germany's defeat in what? World War I? World War II?