In this paper, an empirically stable money demand model for M3 in the euro area is constructed. Starting with a multivariate system, three cointegrating relationships with economic content are found: (i) the spread between the long-term and the short-term nominal interest rates, (ii) the long-term real interest rate, and (iii) a long-run demand for broad money M3. There is evidence that the determinants of M3 money demand are weakly exogenous with respect to the long-run parameters. Hence, following a general-to-specific modelling approach, a parsimonious conditional error-correction model for M3 money demand is derived which can be interpreted economically. For the conditional model, long-run and short-run parameter stability is extensively tested and not rejected.