An electrode member for a muscular electrical stimulation device is disclosed, which can provide a muscle such as an abdominal muscle with an effective stimulation. An electrode member (300), which is applied toa muscular electrical stimulation device (1) utilized to abut against a skin to electrically stimulate a muscle, comprises a sheet-like base material (33) and a plurality of electrodes (311~313) formed on the base material (33). The base material (33) comprises left and right lateral outer edges(33c, 33d) that are respectively configured with more than two gap portions (171~174) having openings. The base material (33) comprises a plurality of base portions (331~343) which are divided by the gap portions (171~174). The plurality of electrodes (311~323) are formed on any one of the plurality of base portions (331~343).