PURPOSE: To prevent effectively deterioration in the quality of a pickled steel strip due to the stop of a pickling line by placing spray nozzles at proper positions between the outlet of a pickling tank and the inlet of a drier in the pickling line and by blowing a mixed fluid consisting of water and air on the surfaces of the steel strip.

CONSTITUTION: In the steel strip pickling line, pairs of spray nozzles 19 are placed between wringer rolls 13 at the outlet of a pickling tank 5 and a hold- down roll 14, between the roll 14 and brush rolls 151, between brush rolls 152 and wringer rolls 16, between the rolls 16 and a hold-down roll 171 in a washing tank 6, and between a hold-down roll 172 in the tank 6 and wringer rolls 10 at the inlet of a drier 7. A mixed fluid consisting of water and air is spouted from the nozzles 19 to wash uniformly both sides of the steel strip 1. A pickling soln. sticking to the strip 1 is washed off. The nozzles 19 are preferably used under such conditions as about 3.5W5kg/cm2 pressure of air and about 1,000W1,500cc/ min flow rate of water.