The purpose of this study was to investigate the influence of air traffic controller's leadership characteristics and hazardous attitudes on the team effectiveness. The effectiveness make use of team efficacy and team commitment. Leadership characteristics and hazardous attitudes make use of the contents of a CRM manual. The study showed following results. 1) Leadership characteristics has a positive influence on the team effectiveness. 2) Hazardous attitudes has a partially bad influence on the team effectiveness. This study was conducted under the auspice of civil and military ATC facilies and by participation of devoting ATC controller's.