A charged particle beam exposure apparatus employs a main deflector made of electromagnetic coils and a subdeflector made of electrostatic deflection electrodes. An exposure method used for this apparatus is capable of shortening a wait time of the main deflector. The main deflector deflects a charged particle beam in a direction X, while the subdeflector deflects the beam around the deflecting position of the main deflector to expose an object to the beam. An area to be exposed on the object is divided into thin subfields such that the width, in an X-axis direction of each subfield, is approximately 1/3 the length in a Y-axis direction of the same.