A charged particle beam apparatus having an aberration correction capability at high acceleration voltages. The charged particle beam apparatus comprises a charged particle beam source; an extraction electrode to extract charged particles from the charged particle beam source; a charged particle beam gun including a means for converging a charged particle beam; an acceleration means for accelerating a charged particle beam emitted from the charged particle beam gun; and an aberration correction means disposed between the charged particle beam gun and the acceleration means, in which an aberration enough to cancel out an aberration of a charged particle beam on the specimen surface is provided to an extraction electrical potential or an equivalent beam at the initial acceleration stage.