An image-forming device includes a conveying part, an image-forming part, first through third sensors, and a control part. The conveying part is configured and arranged to convey a continuous recording material. The image-forming part is configured and arranged to form an image on the recording material conveyed by the conveying part. The first through third sensors are configured and arranged to detect positions of an edge surface of the recording material conveyed by the conveying part. The control part is configured to calculate first through third shifting amounts based on the positions of the edge surface of the recording material simultaneously detected by the first through third sensors, respectively. The first shifting amount is generated by movement of the recording material, the second shifting amount is generated by rotation of the recording material, and the third shifting amount is generated by fluctuations in the edge surface of the recording material.