This diploma thesis has tried to explore the question in which manner a trademark must be used in order not to fall subject to cancellation owing to neglect. In this case, in particular, it has addressed the question of a single entrepreneur who, due to insolvency, has lost his company, but not his trademark. Therefore, the first part of the diploma thesis has focused on the various processes happening in the course of insolvency proceedings. The main question here has been to identify if a trademark can, in fact, be allocated to the mass assets and is thus still utilisable or, if it is rather a personal right, thus connected to the debtor as a person and therefore becomes unexploitable, under the circumstances. It is in this context that the possibility of a free transfer of the brand has been referred to. After making a glimpse in the second part of the diploma thesis, the situation of insolvency under trade law, the third part has addressed its central elements, dealing with a serious, reasonable usage of Section 33a Trademark Protection Act together with a serious reasonable use of the trademark. Now, since a trademark must, in fact, be used not only "in pretence" in order not to fall subject to cancellation, the utilization activities under Section 10a of the Trademark Protection Act as referred to under Section 33a of the same, have been thoroughly examined. Especially the various definitions of the term of usage as given by the European Court of Justice and the Supreme Court of Justice have been closely analysed here. Subsequently, the possibility has been explored to pass the trademark to a licensee. Finally, the last part of the diploma thesis has looked more closely into the new Community trademark. Since the Community trademark, too, must be put to reasonable use, the criteria necessary in this context have been ventilated. Looking briefly into company law has addressed the topics of trademark licence and equity compensation law. Here, the questions have been elaborated as to what might happen when, during a period of crisis, a sharehoder suspends payment for his trademark licence to his company.