An image drawing apparatus configured to draw a plurality of figures in a drawing region having a plurality of scan lines, each figure being constituted by a plurality of vertexes, each vertex being assigned a unique vertex number, the apparatus comprising: a drawing position judging unit configured to judge in respect of each of the plurality of figures whether a figure is drawn on the scan line to be processed, and extract the vertex numbers of each vertex of the plurality of vertexes constituting the figures judged to be drawn on the scan line to be processed; a vertex information reading unit configured to read, with respect to the scan line to be processed, vertex information (VINF) including coordinate information of the vertex, of each of the extracted vertex numbers, from a vertex information memory configured to store vertex information of each of the vertexes constituting the plurality of the figures drawn in the drawing region, at least one of the vertexes being shared by more than one figure of the plurality of figures; an image generating unit configured to generate graphics data of the scan line to be processed based on the read vertex information; and a line buffer configured to store the graphics data generated by the image generating unit, wherein the vertex information reading unit includes: a cache memory configured to temporarily store the vertex information which is part of the vertex information stored in the vertex information memory; a cache tag configured to have entries of all vertex information stored in the vertex information memory, each of the entries storing an address and flag data associated with the vertex number, the address being the address of the cache memory storing the vertex information when the vertex information of the entry is stored in the cache memory, the flag data being a valid flag indicating that the vertex information is stored or an invalid flag indicating that the vertex information is not stored; and a control unit configured to refer to the entry of the cache tag corresponding to the vertex number, and read the vertex information from the address of the cache memory when the flag data indicates the valid flag with respect to the vertex information to be read, and store the vertex information read from the vertex information memory in the cache memory and store the address of the cache memory storing the vertex information in the cache tag in association with the vertex number when the flag data indicates the invalid flag. a drawing position judging unit configured to judge in respect of each of the plurality of figures whether a figure is drawn on the scan line to be processed, and extract the vertex numbers of each vertex of the plurality of vertexes constituting the figures judged to be drawn on the scan line to be processed; a vertex information reading unit configured to read, with respect to the scan line to be processed, vertex information (VINF) including coordinate information of the vertex, of each of the extracted vertex numbers, from a vertex information memory configured to store vertex information of each of the vertexes constituting the plurality of the figures drawn in the drawing region, at least one of the vertexes being shared by more than one figure of the plurality of figures; an image generating unit configured to generate graphics data of the scan line to be processed based on the read vertex information; and a line buffer configured to store the graphics data generated by the image generating unit, a cache memory configured to temporarily store the vertex information which is part of the vertex information stored in the vertex information memory; a cache tag configured to have entries of all vertex information stored in the vertex information memory, each of the entries storing an address and flag data associated with the vertex number, the address being the address of the cache memory storing the vertex information when the vertex information of the entry is stored in the cache memory, the flag data being a valid flag indicating that the vertex information is stored or an invalid flag indicating that the vertex information is not stored; and a control unit configured to refer to the entry of the cache tag corresponding to the vertex number, and read the vertex information from the address of the cache memory when the flag data indicates the valid flag with respect to the vertex information to be read, and store the vertex information read from the vertex information memory in the cache memory and store the address of the cache memory storing the vertex information in the cache tag in association with the vertex number when the flag data indicates the invalid flag.