PURPOSE: To perform uniform dyeing by stirring and circulating a treating liquid through a by-pass line opened on the side face of a treating tank connected to a delivery side of a pump and passing the treating liquid through a main circulation channel comprising carriers, spindles, cheese and the treating tank and returning to the pump.

CONSTITUTION: Cheese dyeing with a vertical package dyeing apparatus 1 is carried out by opening a gate valve 9 branched from the delivery side 8 of a pump 7 prior to the dyeing treatment of a cheese by the forced circulation of a treating liquid containing dye and assistant from the inside of a spindle 3 through the cheese 4 or reverse direction with a pump 7 and the treating liquid is stirred and circulated with the pump 7 using a by-pass line 5 opened on the side face 6 of the tank lower than the level of the carrier 2. Thereafter, the gate valve 9 is closed and a gate valve 10 is opened to transfer the system to the above dyeing treatment stage by forced circulation.