This research is founded on facility personnel¡¦s in hi-tech industries, with two objectives: 1) understand investigate how workers¡¦ personal personality and functional competencies influence their job performance, and 2) establish a criteria for future recruitment. This study uses the Big Five Model developed by McCrae & Costa (1989). The Big Five refers to agreeableness, conscientiousness, extraversion, emotional stability, and openness to experience. In addition, the five functional competencies, identified through expert interviews, include air-conditioning, electricity, fire prevention, environmental protection, safety and damage prevention. In this study, 148 samples were collected. Research methods include descriptive statistics to analyze sample characteristics, reliability analysis to verify validity of tables, and regression analysis to verify the effects of demographic profile, personality, and functional competencies. The findings suggest that agreeableness and conscientiousness positively affect job performance. On functional competencies, fire prevention, safety and damage prevention contribute favorably to job performance. These findings could be used towards recruitment and selection of facility personnel¡¦s, and corporate training to raise companywide performance.