1. A scanning electron microscope device comprising: a charged particle beam irradiating system for irradiating and scanning a specimen having a pattern with a charged particle beam; a charged particle detecting system for detecting charged particles of the kind identical to or different from charged particles emitted from said specimen, which was irradiated and scanned with the charged particle beam by said charged particle beam irradiating system; an image acquiring unit configured for acquiring a charged particle image of said specimen by processing a signal detected by said charged particle detecting system; an image processing unit configured for processing the charged particle image of said specimen acquired by said image acquiring unit; and a storage unit configured for storing plural parameters corresponding to plural imaging conditions for calculating point spread functions; wherein said image processing unit determines a restored image of the acquired image by using a point spread function, which is a function expressing a resolving power deterioration model determined from a dispersion distribution of the charged particles in the specimen.