In this study, we designed and manufactured a 3-axis force sensor for an intelligent gripper that safely grips an unknown object. The 3-axis force sensor consists of an Fx force sensor, an Fy force sensor, and an Fz force sensor in one body, and is manufactured by attaching a strain gauge. The characteristics evaluation showed that the rated output error was within 0.2, the nonlinearity error was within 0.05, and the reproducibility error was within 0.06%. Therefore, the 3-axis force sensor designed and manufactured in this study can be used to measure weight and control the force used to grip an unknown object by attaching it to the intelligent gripper.