The microcensus is an official statistical survey which is carried out annually since 1957 using a representative sample of one percent of the German population and households. In total, about 380,000 households and 820,000 household members participate in the survey. Being designed as a multi-subject survey, the microcensus provides major statistical information about the population structure (including detailed information about migration backgrounds), the framework of families and households as well as employment, income, education and vocational training.For the majority of questions there is an obligation to provide information. Additionally, a set of questions is subject to voluntary response, including information about subjects such as health, health insurance, housing situation or retirement provisions. The supplementary program is repeated at four-year intervals.Given its broad range of variables and its large sample size, the microcensus forms an appropriate data base to analyse small subpopulations, as for example single migrant and occupational groups. Detailed regional analyses increasingly gain significance in scientific research, for example with regard to life chances of different social groups. Results of regional analyses can e.g. be displayed on the level of regional adjustment shifts - regional units of on average 500,000 inhabitants. Furthermore, the high continuity of the survey design allows for (cross-sectional) analyses over time, by which historical developments can be revealed. Being designed as a rotating panel, the microcensus can as well be used for longitudinal analyses. Finally, the microcensus is also suitable for comparisons in an international context since various subjects are adapted to international standards (e.g. the labour force concept).Characterized by its large sampling fraction, a variety of subjects and temporal continuity, the microcensus constitutes an important data source for the social sciences.