Identification of Bug/Insect (with picture)
It is a cockroach, probably a German cockroach nymph.

Cockroaches are well-known pests. According to the Wikipedia link above, there are about 4600 species of cockroaches, 30 of them are associated with human habitats. Cockroaches are extremely resistant and are able to survive in a wide range of environmental conditions. 



@PhysicalFatness pointed out that German cockroach nymphs look very much like your picture and it is likely the species that you've found. Don't be fooled by its name German cockroaches are found all over the world, not only in Germany.