Embodiments are utilized to provide a pelvic floor muscle supporting aid that not only supports the pelvic floor muscles but also is effective for preventing a pelvic organ prolapse. An annular part provided so as to be situated at a position corresponding to an outer peripheral portion of the vaginal opening is pulled by a pulling part, so that an interval between left and right side portions situated on the left and right of the vaginal opening is narrowed. Consequently, not only force to press up the pelvic floor muscles from under is applied but also the vaginal opening is narrowed. Consequently, the pelvic organs do not easily slip out. Therefore, it is possible to prevent urinary incontinence and the like by supporting the pelvic floor muscles and at the same time prevent a pelvic organ prolapse.