The present invention has for its object to provide a charged particle beam irradiation method and a charged particle beam apparatus which can suppress unevenness of electrification even when a plurality of different kinds of materials are contained in a pre-dosing area or degrees of density of patterns inside the pre-dosing area differs with positions.;To accomplish the above object, a charged particle beam irradiation method and a charged particle beam apparatus are provided according to which the pre-dosing area is divided into a plurality of divisional areas and electrifications are deposited to the plural divisional areas by using a beam under different beam irradiation conditions. With the above construction, the electrifications can be deposited to the pre-dosing area on the basis of such an irradiation condition that the differences in electrification at individual positions inside the pre-dosing area can be suppressed and consequently, an influence an electric field has upon the charged particle beam
