A liquid dispensing circuit is provided with: a multi-way cock a first line a second line a third line a fourth line a fifth line and a casing which houses some of the above. When a cock in the multi-way cock is situated in a priming position, a distal opening in a second part of a first flow channel communicates with a first port, and a distal opening in a third part communicates with a second port thus, the first port and the second port are in an open state wherein the ports are connected to each other via the first flow channel, whereas a third port, a fourth port, and a sixth port are in an open state wherein the ports are connected to one another via a second flow channel.