Due to the field aberrations, mainly curvature of image field, astigmatism and field chromatic aberration, it is difficult to obtain a photograph which is of high quality from the center to the corners of the plate. But the aberrations vary greatly with the construction of lens system and the excitation modes of the lenses. This paper describes the possibility of high quality wide field imaging with the aberration minimised JEM-100B.The width of over fringes Dsf caused by the curvature of image field and astigmatism, and the blur ΔF caused by the field chromatic aberration, both in the meridian plane, are given by the following equations based on Glaser's Blenden Freien System: λ: wavelength, λ,K: constant, Ca...Fa,Cv,CF: aberration coefficient, xo: distance from the axis, α: angle of electron beam to the axis.