An image reading device, which is included in an image forming apparatus and used to perform a method of reading images, includes an image reading body configured to read one of a recording medium and the recording medium together with a background area adjacent to the recording medium, a moving body disposed facing the image reading body, and a reference body as a reference in shading correction. The moving body is configured to hold the recording medium and the reference body in a direction intersecting a sheet conveying direction of the recording medium such that the recording medium and the reference body contact to and separate from the image reading body.