A de-skew mechanism, in an image forming device, with a correcting member disposed in a rotatable manner to the rotary shaft and turning with driving roller by a spring between them. A torque spring suppresses the turning of the correcting member to correct the skew of the medium. When conveyed, the medium will butt against the correcting member to be stopped and corrected. The medium conveying force and the force that the spring brings to the driving roller are sufficient for turning the correcting member and passing therethrough. At one time, the force that the correcting member brings to the medium will reduce to zero. As such, the medium will not be damaged by the correcting member while being conveyed.