To provide a method of punching a metal strip in a continuous processing line of the metal strip and the continuous processing line, in which the generation of buckling taking a punched hole in the joined part as a point of origin can be prevented or suppressed.

In a punching equipment 1, the punched hole is punched in the joined part of steel strips 5 by changing the positions of a punch 11 and a die 12 in the width direction so as to suppress the buckling of the steel strip 5 on the basis of the kind of steel, thickness and width of the conveyed steel strip 5.