The purpose of the present invention is to provide a biosignal detection garment which can detect a biosignal continuously and steadily for a long period without giving a wearer a discomfort feeling. The biosignal detection garment according to the present invention is provided with a half-top-type or brassiere-type garment main body part, an under belt which has a fastening tool capable of controlling the size of a chest measurement and is arranged below the garment main body part, at least two electrodes each made from electrically conductive fibers, a connector for attaching a measurement device for detecting a biosignal, and a wiring part for connecting the electrodes to the connector in an electrically conductive manner, said biosignal detection garment being characterized in that the electrodes, the connector and the wiring part are arranged on the under belt, the length of the garment main body part as measured from the top of a shoulder part of the garment main body part to the upper part of the under belt is 20.0 to 35.0 cm inclusive, the under belt has a two-ply bag-like form, and an opening having a size of 1.0 to 10.0 cm inclusive is provided at the center of a front body part.
