PURPOSE: To prevent yellow smoke from emitting in treating spilt coke in coke pushing operation.

CONSTITUTION: A falling material consisting essentially of a tarlike substance is initially received in a spilt coke chute 5 in a slightly opened state of a furnace port without completely removing an oven lid 7 and introduced into water of a spilt coke hopper 6. The oven lid 7 is then completely removed to perform coke pushing operation of the produced cake. After the operation, the falling material consisting essentially of red-hot coke received in the spilt coke chute is subsequently introduced into the water of the spilt coke hopper 6. Thereby, both treatments of the tarlike substance emitting yellow smoke and the spilt coke are separately carried out to prevent the yellow smoke from emitting.