This study aimed to investigate the relationship between individual’s positive affect (NA) / negative affect (PA) and anxiety for disastrous man-made accident, and the moderating effect of internal-external locus of control (LOC) the relationship. Subjective rating scores for PA/NA, anxiety for before and after inducing anxiety experimentally, internal-external LOC, and amount of change in anxiety were collected from 158 university students and analyzed by using correlation analysis and hierarchical regression. The results are as follows. First, PA showed significant negative correlations with anxiety for before and after inducing anxiety, external LOC, and amount of change in anxiety, whereas NA correlated with the variables negatively. Second, the regression coefficient of interaction effect between NA and external LOC was significant, indicating increase in anxiety by inducing anxiety for disastrous man-made accident was prominent when the participant’s NA and external LOC were high. The results suggested that individual’s affectivity as well as cognitive aspects should be considered together to understand anxiety for disastrous man-made accident.