This article deals with the empirical study of well-being. We made an inventory of the research literature, while establishing an overview of the different possible approaches. First, there seems to exist a variety of viewpoints on the subject of study. It is possible to either focus on the situation at a precise moment and observe the living conditions existing at that moment (housing, employment, etc.); or at the presence of sources one can have for modelling the own living conditions (such as income, level of education, etc.). Apart from these studies looking at the situation at a given moment, certain authors are interested in the events occurring in the course of an elapsed period of time (such as a relocation of residence, or a change in employment). In addition to this diversity in the central object of investigation, the researcher has the choice of processing objective and/or subjective data. In this article, we attempt to develop an index of well-being for the Belgian population, following the "living conditions" approach, while using only objective data from a vast sample of individuals and Belgian families. The index presented here therefore constitutes a specific combination of diverse data. These were chosen from indications in the literature concerning the nature and the elements of "well-being", and the characteristics of the available data base. The "fields" integrated into the index are: housing, state of health, social participation and sociability. The established index offers a synthetic instrument from which people can be classified according to the overall measure of their situation in diverse areas of life. This overall view shows that a large majority of Belgians find themselves with average to very positive overall living conditions, while a limited minority is situated below, accumulating negative scores in several areas of life. Another application of this instrument deals with the comparison of the overall profile of specific groups. Such comparisons are developed in this article between groups with diverse demographic, socio-economic and geographic characteristics. Complementary to this development and this application of the objective index, we separately explored the subjective data from the same sample for the level of satisfaction of the respondents and for their experience with diverse emotions. The comparison of this subjective information with the index of objective information shows that, although there is a link between these two phenomena, the correlation remains limited.