A transportation device comprising: a transportation section (19, 20) adapted to transport an object to be detected; and a detection section adapted to detect a transportation amount of the object to be detected which is transported by the transportation section, wherein the detection section includes: a case; a light irradiation section disposed in the case and capable of radiating light on the object to be detected; an optical member which is disposed in the case at a position farther from the object to be detected than the light irradiation section and is adapted to condense a reflected light when the light is radiated from the light irradiation section to the object to be detected; and an imaging section which is disposed in the case at a position farther from the object to be detected than the optical member and is adapted to capture an image by receiving the reflected light condensed by the optical member, characterized in that: the case is fixed at a position closer to the object to be detected than the optical member, the case is configured by bonding a plurality of members (31, 32, 33), and coefficients of linear expansion of each of the members are the same as each other. a transportation section (19, 20) adapted to transport an object to be detected; and a detection section adapted to detect a transportation amount of the object to be detected which is transported by the transportation section, wherein the detection section includes: a case; a light irradiation section disposed in the case and capable of radiating light on the object to be detected; an optical member which is disposed in the case at a position farther from the object to be detected than the light irradiation section and is adapted to condense a reflected light when the light is radiated from the light irradiation section to the object to be detected; and an imaging section which is disposed in the case at a position farther from the object to be detected than the optical member and is adapted to capture an image by receiving the reflected light condensed by the optical member, characterized in that: the case is fixed at a position closer to the object to be detected than the optical member, the case is configured by bonding a plurality of members (31, 32, 33), and coefficients of linear expansion of each of the members are the same as each other. a case; a light irradiation section disposed in the case and capable of radiating light on the object to be detected; an optical member which is disposed in the case at a position farther from the object to be detected than the light irradiation section and is adapted to condense a reflected light when the light is radiated from the light irradiation section to the object to be detected; and an imaging section which is disposed in the case at a position farther from the object to be detected than the optical member and is adapted to capture an image by receiving the reflected light condensed by the optical member, characterized in that: the case is fixed at a position closer to the object to be detected than the optical member, the case is configured by bonding a plurality of members (31, 32, 33), and coefficients of linear expansion of each of the members are the same as each other. the case is fixed at a position closer to the object to be detected than the optical member, the case is configured by bonding a plurality of members (31, 32, 33), and coefficients of linear expansion of each of the members are the same as each other.