Abstract: [Problem] An object of the present invention is to provide an attachment fixture that facilitates appropriate mounting of a physical information acquisition device that performs sensing inside a user's body. [Solution] The present invention to solve the above problems is an attachment fixture 1 that can attach a physical information acquisition device 2 that measures physical information of a user by emitting a measurement wave including a millimeter wave or a microwave from an emission and entrance surface 22 toward the user to a belt 3, the attachment fixture including: an attachment fixture body 11 (Q); a mounting portion that can be mounted to a waist part of the user; and an attachment portion 12 to which the physical information acquisition device 2 can be attached.