<p>A washing brush for an endoscope inserted into the tube of the endoscope, comprising a long flexible shaft and a brush part fitted to the tip of the shaft. The brush part is formed of bristles and a twisted wire. The shaft comprises a small diameter part smaller in outer diameter than the other portions at a portion where the bristles are overlapped with each other in the fallen state of the bristles toward the tip part side-face of the shaft. A dimension obtained by adding the outer diameter of the small diameter part to the outer diameters of two pieces of bristles is smaller than the inner diameter of the tube in which the washing brush is inserted.</p>
