An image reading device comprising: a first reading unit configured to move between a first position and a second position; a second reading unit disposed to be more separate from the second position than the first reading unit in a movement direction of the first reading unit from the second position to the first position, and configured to move in a same direction as the first reading unit at a speed half of a moving speed of the first reading unit in conjunction with a movement of the first reading unit; a control portion disposed below the first reading unit and more on a second position side than any position within a movement range of the second reading unit; a cable connected from the first reading unit to the control portion via the second reading unit, so as to form an upper portion of the cable from the first reading unit to the second reading unit, and a lower portion of the cable from the second reading unit to the control portion; and a guide member that is formed to project from the second reading unit toward the first reading unit and supports part or all of the cable between the first reading unit and the second reading unit, wherein the first reading unit includes: a light source configured to emit light toward a document sheet; and a first light guide member configured to guide, to the second reading unit, the light which was emitted from the light source and reflected on the document sheet, and the second reading unit includes: a second light guide member (231, 232) configured to guide the light from the first reading unit member to a photoelectric converting element, characterized in that the guide member has a length that can support the upper portion of the cable so as to prevent contact between the upper portion and the lower portion, and the first reading unit comprises an opening, and the guide member passes through the opening of the first reading unit in a state where the first moving body is at the first position. a first reading unit configured to move between a first position and a second position; a second reading unit disposed to be more separate from the second position than the first reading unit in a movement direction of the first reading unit from the second position to the first position, and configured to move in a same direction as the first reading unit at a speed half of a moving speed of the first reading unit in conjunction with a movement of the first reading unit; a control portion disposed below the first reading unit and more on a second position side than any position within a movement range of the second reading unit; a cable connected from the first reading unit to the control portion via the second reading unit, so as to form an upper portion of the cable from the first reading unit to the second reading unit, and a lower portion of the cable from the second reading unit to the control portion; and a guide member that is formed to project from the second reading unit toward the first reading unit and supports part or all of the cable between the first reading unit and the second reading unit, wherein the first reading unit includes: a light source configured to emit light toward a document sheet; and a first light guide member configured to guide, to the second reading unit, the light which was emitted from the light source and reflected on the document sheet, and a light source configured to emit light toward a document sheet; and a first light guide member configured to guide, to the second reading unit, the light which was emitted from the light source and reflected on the document sheet, and the second reading unit includes: a second light guide member (231, 232) configured to guide the light from the first reading unit member to a photoelectric converting element, characterized in that a second light guide member (231, 232) configured to guide the light from the first reading unit member to a photoelectric converting element, characterized in that