PURPOSE: To check a defect of a mask reticle with a high precision by using a filter through which the light having a wavelength selected from wavelength range 400 to 190nm of the radiated light of a light emission source is transmitted.

CONSTITUTION: A light emission source 1, an optical system 3 which converts the radiated light of this source 1 to two parallel beams 2, filters 4 provided on respective optical axes of these two parallel beams 2, and an X-Y stage 6 which faces these two parallel beams 2 and on which a body 5 to be checked is placed are provided. In this case, filters through which the light having a wavelength selected from wavelength range 400 to 190nm of the radiated light of the light emission source 1 is transmitted are used as filters 4. That is, the defect of the mask reticle is checked by the light having the same wavelength as the light used for actual exposure. Thus, the defect of the mask reticle is checked with a high precision.