An image reading device and a method for manufacturing the same are provided, where the image reading device is capable of being assembled more efficiently. The image reading device includes: an optical part, extending long in a direction; a case, having an accommodating portion for accommodating the optical part; and a light receiving component, accommodated in the case. The optical part is fixed in the accommodating portion through a first adhesive and a second adhesive with hardening time longer than that of the first adhesive.