Deflection sensitivity calculation method and deflection sensitivity calculation system

A deflection sensitivity calculation system for calculating deflection sensitivity of a deflector in an electron beam irradiation apparatus that irradiates an irradiation object on a stage with an electron beam by causing the deflector to deflect the electron beam, the deflection sensitivity calculation system comprising:

• an adjustment plate that detects a current corresponding to the irradiated electron beam, a size of the adjustment plate being known, the adjustment plate being placed on the stage;
• an ammeter that detects a current detected from the adjustment plate while an area that covers the adjustment plate is irradiated with the electron beam by scanning a deflection parameter that controls deflection of the deflector in a predetermined width;
• an image forming module that forms an image corresponding to the detected current value;
• a number of pixels calculator that calculates a number of pixels of a portion corresponding to the adjustment plate in the formed image;
• and
• a deflection sensitivity calculator that calculates the deflection sensitivity of the deflector based on a size of the adjustment plate, the predetermined width for scanning the deflection parameter, the number of pixels of the image, and the number of pixels of the portion corresponding to the adjustment plate in the image.