It is difficult to introduce insulin self-injection because of troublesomeness of injection, fear of needles, and psychological barriers such as pain. Injection needles used in Japan have a needle hub with a projecting basal part fixing a needle tube (hereinafter called “Needle A”). Meanwhile, there are injection needles with a flat skin contact structure overseas (hereinafter called “Needle B”). We studied how the shapes of these two types of injection needles (needle hub) would give visual impression to users. The study was conducted through the Internet in 2,004 subjects who have no experience of insulin self-injection. The rate of subjects who fear the needle was 46.1% and 38.4% for Needle A and Needle B, respectively. And the rate of subjects who think the injection needle looks like painful was 55.5% and 50.8% for Needle A and Needle B, respectively. The rate of subjects who think the injection needle easily bends was 50.0% and 18.9% for Needle A and Needle B, respectively; and the rate of subjects who think the injection needle easily breaks was 43.9% and 21.0% for Needle A and Needle B, respectively. The rate of subjects who want to use this injection needle if they receive injection conclusively was 28.3% and 59.5% for Needle A and Needle B, respectively; and the rate of Needle B was significantly high (p<0.001). The impression of injection and self-injection was greatly divided by the shapes of the needle hub, and this difference caused a significant difference in an impression related to the safety in addition to feeling of use in this study. Based on the results of this study, we concluded that NovoFine® Plus 32G 4mm needle, Needle B, is a needle that enhances a sense of safety of users.