To improve product lifetime as well as to increase wearing feeling, maintainability and productivity, and to suppress manufacturing costs and expenses of the user. A portable electronic device 10 includes a device body 20 arranged inside a garment W and housing an electronic component and a fixing member 30A formed separately from the device body 20 and arranged outside the garment W, which fixes the device body 20 so as to be attached and detached to and from the garment W in a state of sandwiching the garment W between the fixing member 30A and the device bogy 20 from the other side of the garment W. The fixing member 30A is formed so as to be elastically deformed, which is formed in a ring shape surrounding the device body 20. Gaps are provided on both sides of the device body 20 in the radial direction of the fixing member 30A between an inner peripheral surface of the fixing member 30A and the device body 20.