An inspection apparatus includes: beam generation means for generating any of charged particles and electromagnetic waves as a beam; a primary optical system that guides the beam into an inspection object held in a working chamber and irradiates the inspection object with the beam; a secondary optical system that detects secondary charged particles occurring from the inspection object; and an image processing system that forms an image on the basis of the detected secondary charged particles. The primary optical system includes a photoelectron generator having a photoelectronic surface. The base material of the photoelectronic surface is made of material having a higher thermal conductivity than the thermal conductivity of quartz. A central portion of the inspection object is provided with a central flat portion 390. The periphery of the central flat portion 390 is provided with peripheral flat portion 392 via a step 391. The periphery of the step 391 is provided with an electric field correction plate 400. A surface voltage equivalent to a surface voltage applied to the inspection object is applied to an electrode 401 on the electric field correction plate 400.