An endoscope washing and disinfecting apparatus according to the present invention includes an apparatus body having a washing tub for placing and washing an endoscope, a brush forward and reverse mechanism provided with a fluid supply part for supplying a fluid circulating in the apparatus body into a conduit of the endoscope, and a washing brush cassette freely attachable and detachable to/from the brush forward and reverse mechanism, having a washing brush for brush washing the inside of the conduit by moving forward and reversely by the brush forward and reverse mechanism through the fluid supply part. Thus, an inexpensive endoscope conduit washing brush cassette capable of readily changing a washing brush and an easy-to-use endoscope washing and disinfecting apparatus corresponding to the endoscope conduit washing brush cassette can be provided.
