PURPOSE: To improve workability of a multiple liquid (two liquid) mixing device and to secure certain and stable movement.

CONSTITUTION: To the middle of respective supply routes from a main agent pump 100 and a hardening agent pump 200, a supply route from a cleaning agent pump is connected, and by providing three-way valves 500, 600 respectively here, it is made possible to select one of the routes. Additionally, on the downstream of a contact point, a route toward a mixer 400 and a branch route to lead liquid in the different direction are provided, and by providing three-way valves 550, 650 respectively here, it is made possible to select either of the routes. These three-way valves are made to carry out switching work under control of a control part 800 in accordance with indication input.