A glass bottle inspection device comprising: rotating means for rotating a glass bottle about a bottle axis; mouth portion light emitting means for emitting light onto a bottle mouth of the glass bottle; mouth portion image taking means for taking an image of the bottle mouth onto which the light is emitted from the mouth portion light emitting means; base portion light emitting means for emitting light onto a base portion of the glass bottle; and base portion image taking means for taking an image of the base portion onto which the light is emitted from the base portion light emitting means, wherein the base portion image taking means includes a telecentric lens unit and a camera, wherein the telecentric lens unit comprises a central reflector, two reflective plates, and a telecentric lens that are disposed in a box-shaped main body, the main body having an entrance on a front side thereof and an exit on a back side thereof, wherein the central reflector has a triangular pole shape and is vertically arranged such that one vertex thereof faces the back side of the box-shaped main body, and regions on both left and right sides of the central reflector serve as the entrance, of the two reflective plates, one is vertically arranged at a location spaced away from the left side of the central reflector and another one is vertically arranged at a location spaced away from the right side thereof, the telecentric lens is fixed behind the central reflector, and a region behind the telecentric lens serves as the exit, and light incident through the entrance is reflected by the reflective plates, then reflected by reflection planes on both sides of the vertex of the central reflector, passes through the telecentric lens, and exits through the exit to take an image of a bottle to be inspected, wherein the positions of the two reflective plates are adjusted so as to match with adjacent areas of the left and right ends of a bottle to be inspected such that only an image of adjacent areas of both left and right ends of the bottle base portion is taken, and no image of the central portion is taken; and wherein two predetermined points G and H at a top of the bottle mouth are detected from the image of the mouth portion taken by the mouth portion image taking means, two predetermined points M and N at the bottom of the bottle base portion are detected from the image of the base portion taken by the base portion image taking means, the image of the base portion being taken simultaneously with the image of the mouth portion, and a top inclination of the bottle being in a vertical state is calculated from the two points G and H in the mouth portion and the two points M and N in the base portion. rotating means for rotating a glass bottle about a bottle axis; mouth portion light emitting means for emitting light onto a bottle mouth of the glass bottle; mouth portion image taking means for taking an image of the bottle mouth onto which the light is emitted from the mouth portion light emitting means; base portion light emitting means for emitting light onto a base portion of the glass bottle; and base portion image taking means for taking an image of the base portion onto which the light is emitted from the base portion light emitting means, wherein the base portion image taking means includes a telecentric lens unit and a camera, wherein the telecentric lens unit comprises a central reflector, two reflective plates, and a telecentric lens that are disposed in a box-shaped main body, the main body having an entrance on a front side thereof and an exit on a back side thereof, wherein the central reflector has a triangular pole shape and is vertically arranged such that one vertex thereof faces the back side of the box-shaped main body, and regions on both left and right sides of the central reflector serve as the entrance, of the two reflective plates, one is vertically arranged at a location spaced away from the left side of the central reflector and another one is vertically arranged at a location spaced away from the right side thereof, the telecentric lens is fixed behind the central reflector, and a region behind the telecentric lens serves as the exit, and light incident through the entrance is reflected by the reflective plates, then reflected by reflection planes on both sides of the vertex of the central reflector, passes through the telecentric lens, and exits through the exit to take an image of a bottle to be inspected, wherein the positions of the two reflective plates are adjusted so as to match with adjacent areas of the left and right ends of a bottle to be inspected such that only an image of adjacent areas of both left and right ends of the bottle base portion is taken, and no image of the central portion is taken; and wherein two predetermined points G and H at a top of the bottle mouth are detected from the image of the mouth portion taken by the mouth portion image taking means, two predetermined points M and N at the bottom of the bottle base portion are detected from the image of the base portion taken by the base portion image taking means, the image of the base portion being taken simultaneously with the image of the mouth portion, and a top inclination of the bottle being in a vertical state is calculated from the two points G and H in the mouth portion and the two points M and N in the base portion.