An image reading device includes a conveyor unit that conveys a document along a conveying path for ADF-type image scanning including a curved path. The conveyor unit includes a conveyor roller that reverses a conveying direction of the document in the curved path. The device further includes a first contact surface that comes into contact with a first side of the document when the document is conveyed, a second contact surface that comes into contact with a second side of the document when the document is conveyed, a first reading unit that reads an image on the first side of the document, and a second reading unit disposed above the second contact surface and reading an image on the second side of the document. A part of the conveyor roller is disposed lower than the first and second contact surfaces in an up down direction of the image reading device.