An image reading device is configured such that, when first and second external devices are designated as destinations of image data, a controller of the image reading device controls an image reader to read an image on the original and generate image data, stores the image data in a storage, transmits the image data stored in the storage to the first external device, determine whether transmission of the image data to the first external device is successfully completed, transmits the image data stored in the storage to the second external device, determine whether transmission of the image data to the second external device is successfully completed. When transmission of the image data to the first external device is successfully completed and transmission of the image data to the second external device is failed, the controller transmits a deletion instruction to delete the image data to the first external device.