PROBLEM TO BE SOLVED: To provide a preliminary washing device for endoscopes for preliminarily washing an endoscope, that eliminates any possibility of damaging an endoscope by a washing brush in a washing tank and can perform the preliminary washing for the endoscope in security.SOLUTION: The preliminary washing device includes a washing tank 2 securing a washing space of an endoscope 50, and a washing brush 3 being insertable in a duct inside the endoscope 50. The washing tank 2 has a fixing member 23 detachably fixed to the endoscope 50 at an edge part thereof, namely, a part of four corners inside the washing tank 2.
