Technology start-up companies are known as a modern working environment that mostly consists of millennials generation. However, the data shows that the number of women in the industry, especially in a senior position, is not many. Naturally, men have a high sense of competitiveness and ego where they do not want to be defeated by women for getting managerial positions. While women sometimes think they are not capable enough or have time to take more responsibility as leaders. Hence, this study is developed to understand both men and women attitudes to female managers, particularly in tech-startup companies in Jakarta. This study will use the mixed method or conducting quantitative and qualitative analysis. “Women as Managers Scale (WAMS)” is used in the quantitative method and become the basis for developing questions in an interview or qualitative analysis. The quantitative data are collected from 60 male and 60 female that work in Jakarta technology start-up companies. While three men and three women are being interviewed for the qualitative approach. The study found the difference in the attitude between men and women towards female manager in the technology startup companies in Jakarta, Indonesia. Higher attitudes differences between men and women are in terms of ability and physical constraint. The main reason behind that because men do not agree with the statement women are more competitive than men, and men believe that menstruation and pregnancy can bring harm or negative effect. While in terms of acceptance and leadership, the attitude differences are not high. The difference is only due to women who can give a more detailed answer compare to men. Keywords: Female manager, Technology, Start-up, Women as Manager Scale (WAMS), Indonesia.