PROBLEM TO BE SOLVED: To provide a medical drainage device 1 contributing to prevention of retrograde infection by stopping a part of an effluent from being sucked into a guide tube 6 when the guide tube 6 is evacuated and preventing intrusion of the effluent into the guide tube 6.SOLUTION: An elastic modulus of a second check valve 6a is set smaller than an elastic modulus of a first check valve 5a. After an effluent is discharged by contractingly deforming a pump valve 8 by a gripping operation, the gripping operation applied to the pump valve 8 is released, and when the guide tube 6 is evacuated, the second check valve 6a is closed before the first check valve 5a is opened. This configuration stops a part of the effluent from being sucked into the guide tube 6 when the guide tube 6 is evacuated so as to prevent the intrusion of the effluent into the guide tube 6, thereby contributing to the prevention of the retrograde infection.
