Working environments are becoming far more diverse. For example, Activity-Based Working (ABW), a new style of working where workers choose their own work environment, is now attracting attention. An office that introduces ABW is comprised of various spaces, including open plan workspaces, corresponding to the ways of working. However, such an office may result in distraction. Therefore, it is necessary to identify the environmental factors that affect individual workers’ concentration at work. This study aimed to ascertain the relationship between individual workers’ attributes, such as the Big Five personality traits, personal control, and age, and the factors that distract them from their work. A questionnaire-based field survey was conducted at an office that partially adopted ABW to investigate the relationship between selection of seats and concentration at work. The results revealed different tendencies among workers for the type of work environment needed to concentrate according to their individual attributes. Additionally, it was suggested that the changing of seats lead to improved concentration at work, thus increasing productivity.