Pattern inspection method and pattern inspection apparatus

A pattern inspection method using a pattern inspection apparatus comprising a support member configured to support a specimen, an optical system configured to irradiate light from a light source to the specimen, an imaging sensor configured to image a pattern formed on the specimen while relatively moving the specimen in a first direction, an inspection part configured to perform a defect inspection using an image of the pattern, and a feedback circuit configured to correct a position in a gravity direction of the specimen using autofocusing when the pattern is imaged, the method comprising

• mounting a reference specimen of a same material as that of the specimen on the support member and creating a map indicating a distortion in a gravity direction of the reference specimen;
• mounting the specimen on the support member and irradiating light from the light source to the specimen;
• correcting a linear component of a distortion in a gravity direction of the specimen between a first point on the specimen and a second point located in the first direction on the specimen on a basis of a first difference in the gravity direction between the first point and the second point in the map, and correcting at least a secondary component of the distortion in the gravity direction of the specimen using the feedback circuit, when the pattern is imaged while a position of the specimen with respect to light from the light source is relatively moved in the first direction;
• and
• performing a defect inspection using an image of the pattern.