Based on a micro-level approach and using data from the European Working Conditions Survey, covering 27 countries, we analyze the determinant factors of job quality. To that end, through cluster analysis applied to 11 dimensional indices, we form three more homogeneous country groups and identify, by estimating twice-censored Tobit models, the main determinant factors affecting the individual level of job quality in each group. We verify the relevance of variables related to worker characteristics, firm characteristics, and the country in which the individual works. Among worker characteristics, education and employment status are the factors with the highest impact on job quality, while the economic sector is the most important firm characteristic. The results suggest the existence of important differences among groups regarding the magnitude of the impact of some factors. The highest dissimilarities are found between the group with better jobs (Nordic countries plus Belgium) and the group with lower quality jobs (Central and Eastern Europe countries plus Portugal and Greece). Variables related with age, education, dimension of the firm, and economic sector are those in which more heterogeneity is found among the groups.