A fixing device includes a vaginal insertion portion of a longitudinal shape which is inserted into the vagina, a urethral-insertion member having a urethral-insertion portion of a longitudinal shape which is inserted into the urethra, and an interlock portion which is interlock means configured to interlock the vaginal insertion portion and the urethral-insertion member with each other. The vaginal insertion portion has a form of a plate and is curved. Further, the vaginal insertion portion has, as a guide portion which supports a medical tool of a longitudinal shape for movement along a longitudinal direction of the medical tool so as to guide the medical tool in the proximity of the urethra and in a direction in which the medical tool bypasses the urethra, two guide holes and which extend through the vaginal insertion portion in a thicknesswise direction of the vaginal insertion portion.
