An object of the present invention is to provide a biosignal detecting garment capable of continuously and stably detecting a biosignal for a long period of time without causing discomfort to a wearer. The biosignal detecting garment of the present invention includes a crop top type or brassiere type garment body, an under belt that have a fastening tool capable of adjusting a chest circumference size and that is disposed in a lower portion of the garment body, at least two or more electrodes formed of an electroconductive fiber, a connector for installing a measurement device configured to detect a biosignal, and a wiring portion that electrically connects the electrodes and the connector. The electrodes, the connector, and the wiring portion are installed in the under belt, the garment body has a length from an apex of a shoulder portion of the garment body to an upper portion of the under belt of 20.0 cm or more and 35.0 cm or less, the under belt is formed in a bag shape with two pieces stacked, and an opening portion with a range of 1.0 cm or more and 10.0 cm or less is provided at a center of a front body piece.