Abstract: A coupling device intended to prevent impurities such as dust and particles adhering to the end face of a solution supplying male pipe 2 from being mixed with a high purity chemical solution N, which will be supplied through the device, not to degrade the purity of the solution. It includes a check valve 7 arranged in that end portion of a solution passage 5 in the male pipe 2 which is inserted into a cleaning chamber 15, a valve pusher 44a arranged in that end portion of a solution passage 43 in a solution supplied female pipe 3 which is connected to the passage 5 in the male pipe 2 to push the check valve 7 to open the passage 5, a valve system for opening and closing the passage 43 when the female pipe 3 is reciprocated in the axial direction, and a check valve 51 located on the outlet side of a cleaning liquid passage 48.