A charged particle beam apparatus has a charged particle beam column configured to irradiate a charged particle beam, and a controller configured to control the charged particle beam column to irradiate the charged particle beam at a first pixel interval for a first region and to irradiate the charged particle beam at a second pixel interval different from the first pixel interval for a second region included in the first region. The first and second regions include plural first and second pixels each including first and second sub-pixels which are irradiated by the charged particle beam to generate secondary electrons. First and second sub-pixel images are formed based on the detected secondary electrons, and the first and second sub-pixel images are synthesized to form first and second images.