This article presents a proposal for a questionnaire diagnosing the well-being of employees in terms of eudemonia. This questionnaire stems from two theories on psychological and social well-being, already used in positive psychology. The construction of this questionnaire and its subsequent confirmatory studies were conducted on the group of 724 working adults. In the final questionnaire version, four factors were distinguished: positive organization; fit and development; positive relations with co-workers; and contribution to the organization. Additionally, by using the K-means cluster analysis (N = 609), four specific well-being profiles were distinguished: (1) moderate well-being based on relationships, (2) globally high well-being in the workplace, (3) globally low well-being in the workplace, (4) reduced well-being based on their own competences. Further analysis showed that people representing these profiles differ from each other in their level of attachment to the workplace. The guidelines regarding the actions of employers to increase the eudemonic well-being of their employees are also discussed.