The purposes of this study are to investigate college students' attitudes toward ChatGPT and to understand whether gender makes any difference in their attitudes. We developed the ChatGPT attitude scale (CAS) and administrated it to a sample of 516 Taiwan college students. Through an exploratory factor analysis, the 5-T (Tool, Tutor, Talk, Trend, and Threat) model of CAS was extracted and validated via confirmatory factor analysis. The CAS exhibited good reliability and validity and can be used to explain ChatGPT attitudes. According to our findings, university students consider ChatGPT an important "Tool" in their daily life. Additionally, ChatGPT plays a significant "Tutor" role, assisting with language translation and knowledge learning. Besides its utilitarian functions, ChatGPT also serves as a "Talk" feature, offering interactive chat and emotional support. Currently, students also acknowledge ChatGPT as an important "Trend" of the times, but they are also deeply concerned about the potential "Threat" of content falsification and job displacement brought on by ChatGPT. In terms of gender differences, compared to females, males scored higher than females in the total scale and in the Tool, Tutor, and Trend subscales. However, there was no significant difference between males and females in the Talk and Threat subscales. This gender difference result differs from previous research on robots or social media.