To provide an inspecting device which can accurately and easily inspect asymmetrical aberrations of high order remaining in the optical system.

This inspecting device is equipped with image detecting means (116 and 117) for detecting an image of a pattern formed through image formation optical systems 107 to 115 and a defocusing means 122 which defocuses the image of the pattern detected by the image detecting means. On the basis of variation of the asymmetry of the image corresponding to the edge of the pattern in different defocusing states by the detecting means and the position shifts of the pattern image detected in the defocusing states by the image detecting means at right angles to the optical axes of the image formation optical systems 107 to 115, the aberrations which are the aberrations remaining in the optical systems 107 to 115 and concerned in the detection direction of the image of the pattern are inspected.