To solve a problem that there is not a means for accurately and safely guiding a fine laser beam to a pinhole when a laser beam is used for locally heating and padding the pinhole caused in light alloy casting operation.

A pinhole correcting apparatus is constituted so that a microscope to be directed to the inside of a housing is positioned above the housing with an opening provided that can be opened/closed with a cover, and a laser heating means for radiating a laser beam in the optical axis direction is installed in the microscope, and a supporting means for supporting a light alloy casting in the front in the optical axis direction of the microscope is positioned inside the housing.