To provide a device for cooling, heating or drying a steel strip by spraying a refrigerant or a heating medium capable of consistently passing the steel strip while preventing any fluttering or twisting phenomenon even when the shape of the steel strip is defective.

In the device for cooling, heating or drying the steel strip by spraying the refrigerant or the heating medium from refrigerant or heating medium spraying boxes opositely disposed on face and back sides of the steel strip, a pair of baffle plates for adequately adjusting a space between the spraying boxes facing each other, in particular, only the space in the vicinity of right and left edges of the steel strip are installed on each spraying box. By adjusting the space by the baffle plates, the flow of the refrigerant or the heating medium is changed on the face and back sides of the steel strip, and the steel strip is consistently passed by generating the differential pressure between the face and back sides of the steel strip at the edges of the steel strip.