To provide an automatic washing apparatus and a connecting structure for a vacuum piping type milking machine.

Provided is the washing apparatus for the milking bucket installed on the vacuum piping type milking machine comprising a cleaning tank attached to the vacuum piping type milking machine, a cleaning liquid feeding means to the cleaning tank and a cleaning liquid circulating means which cleans a milk collecting piping of the vacuum piping type milking machine by circulating the cleaning liquid in the cleaning tank, wherein the washing apparatus for milking bucket is provided with a cleaning liquid sucking means for sucking the cleaning liquid into the milking bucket from the cleaning tank, and a cleaning liquid delivery means for delivering the cleaning liquid after cleaning the milking bucket to the milk collecting piping by using vacuum pressure of the vacuum piping type milking machine.