The present invention provides an electron beam writing apparatus and an image placement error correcting method each capable of calculating a high-accuracy correction amount relative to an image placement error in consideration of a difference in required unit area of height distribution data between the shape of a back surface of an EUV mask and the shape of a surface of a pin chuck. Of back surface shape data of the EUV mask necessary to perform an image placement error correction of each pattern, the back surface shape data of a position brought into contact with each pin of the pin chuck is extracted. The image placement error is calculated only from the extracted back surface shape data.