Charged particle beam writing apparatus, discharge detection method, and discharge detection apparatus

A charged particle beam writing apparatus comprising:

• an emission unit configured to emit a charged particle beam;
• a high-voltage power supply configured to apply an acceleration voltage for charged particles to the emission unit;
• a deflector configured to deflect the emitted charged particle beam;
• a stage configured to mount thereon a target object to be irradiated with the charged particle beam and to be written;
• a discharge sensor configured to output an output value indicating a change in a case where a discharge occurs in a column in which the emission unit and the deflector are arranged or in the high-voltage power supply;
• and
• a discharge detection control unit configured to convert the output value from the discharge sensor into a conversion value with the same sign, calculate an integral value of the conversion value over a fixed period of time, and determine, based on the integral value, whether or not a discharge that causes a pattern error has occurred.