Patent ID: 8878129

Claim:
A pattern measurement apparatus, comprising: a scan controller configured to control a scanning direction of an electron beam; a focus controller configured to control a focus position of the electron beam; a stage configured to have a substrate placed on the stage, a pattern being provided in the substrate; a sensor configured to sense secondary electrons due to the electron beam irradiated onto the pattern; a signal processor configured to process a signal sensed by the sensor; and a measurement unit, the signal processor being configured to determine at least one of third signals from at least one of first signals and at least one of second signals, the first signals being obtained by the sensor by the electron beam being scanned by the scan controller in a first direction, the second signals being obtained by the sensor by the electron beam being scanned by the scan controller in a second direction opposite to the first direction, a signal difference caused by the scanning direction of the electron beam being suppressed for the third signals, the measurement unit being configured to measure a position of the pattern from the third signals.