There is an abundant literature analysing the salary or pension gaps between the sexes. However, wealth inequalities remain a topic that has been little explored. Wealth is an important indicator of economic well-being, whether one focuses on the inequalities within the population as a whole or, more specifically, within the household. We use the data from the French Wealth surveys of 2004 and 2010 to allocate wealth to each member of the household, in particular between couples. We thus evidence a mean gross wealth for all men that is approximately 15% greater than that of women. A breakdown of the wealth shows that the gaps are wider for financial assets (roughly 37%) than for real estate (4% for the main residence in 2010) which accounts for the greatest part of the wealth of households. This can be explained by the fact that more often than not the home is owned by the couple in equal shares. To highlight the factors explaining these wealth gaps, we use the semi-parametric decomposition method of DiNardo, Fortin & Lemieux (1996) which breaks down the differences not only at the level of the mean (the Oaxaxa and Blinder method usually used) but also at other points of the wealth distribution. Wealth is indeed highly dissymmetrical. We show that the wealth gaps between men and women are essentially due to differences of distribution of individual characteristics, in particular those related to the labour market (income, position and experience). This is partly offset by slightly greater wealth at given characteristics. This phenomenon may reflect different attitudes with respect to savings but also the compensatory effect of the partial pooling of resources within households.