Burnout as a concept indicative of a work-related state of mental exhaustion is recognized around the globe. Although the Maslach Burnout Inventory is by far the most frequently used questionnaire for assessing burnout, it is associated with several shortcomings and has been criticized on theoretical as well as empirical grounds. Thus, there is a need for an alternative questionnaire with a strong conceptual basis and proper psychometric qualities. This challenge has been taken up by introducing the Burnout Assessment Tool (BAT), according to which burnout is conceived as a work-related state of exhaustion among employees, characterized by extreme tiredness, reduced ability to regulate cognitive and emotional processes, and mental distancing. Given that the BAT is a new measure of burnout, its psychometric properties need to be examined. This paper focuses on an evaluation of the internal construct validity of the BAT using Rasch analysis in two random samples (n = 800, each) drawn from larger representative samples of the working population of the Netherlands and Flanders (Belgium). The BAT has sound psychometric properties and fulfills the measurement criteria according to the Rasch model. The BAT score reflects the scoring structure indicated by the developers of the scale and the BAT’s four subscales can be summarized into a single burnout score. The BAT score also works invariantly for women and men, younger and older respondents, and across both countries. Hence, the BAT can be used in organizations for screening and identifying employees who are at risk of burnout (download full article).