Electron beam drawing apparatus and electron beam drawing method

An electron beam drawing apparatus comprising:

• an electron gun including a cathode that emits an electron beam, an anode, and a Wehnelt arranged between the cathode and the anode;
• a power supply circuit including a high-voltage power supply that applies an acceleration voltage between the cathode and the anode, and a current control circuit that controls a total emission current;
• a first detector that detects a first emission current from an outer peripheral portion of the cathode, the first emission current being part of the total emission current;
• a stage on which a substrate as a drawing target is placed;
• a second detector that detects a second emission current from an central portion of the cathode, the second emission current being part of the total emission current;
• and
• a controller that determines a coefficient, which is a ratio of an emission current from the outer peripheral portion of the cathode to the first emission current, by employing the total emission current, the first emission current, and the second emission current,
• wherein, during a period in which a pattern is drawn on the substrate, the controller estimates a value of the second emission current by subtracting a value, which is resulted by multiplying the first emission current by the coefficient, from the total emission current, and controls the current control circuit in a manner of holding the estimated value constant.