The purpose of this study was to categorize spectators in Albirex Niigata’s home games from the aspect of spectator motives and to clarify the characteristics of sports spectators, who constitute a mature market for professional sports. A total of 3,312 samples were classified into four clusters through non-hierarchical cluster analysis by applying the sports spectator motivation scale (Performance, Social, Achievement, Escape, and Drama). One-way analysis of variance, multiple comparisons, chi-square test, and residuals analysis were performed to understand the characteristics of each cluster. Then, based on the characteristics, these clusters were named floating spectators, introverted spectators, habitual spectators, and enthusiastic spectators. The floating spectators cluster was composed of people with weaker commitment and involvement with the club. This segment showed low scores on all sports spectator motivation factors and had a significantly higher proportion of fans in their 40s and first-year fans than other segments. The introverted spectators had a significantly higher percentage of those who had supported the club for 2-4 years. It showed high scores for Performance, Achievement, Escape, and Drama, but a low score for Social. The habitual spectators had a significantly higher proportion of fans who were older adults and had been supporting the club for more than 10 years compared with other segments, and they also had lower scores for Escape and Drama. These scores suggested that such fans expect a type of scheduled victory for the club and that watching games in the stadium has become a part of their daily lives. Finally, in the enthusiastic spectators, the percentage of fans in their 20s and younger was significantly higher, and they had a strong commitment and involvement in the club. Albirex Niigata is expected to realize sustainable growth by developing and implementing a marketing strategy that reflects the characteristics of each segment.