PURPOSE: To provide a method and device for inspecting plated-through soldered joints by which defects can be easily detected at low costs.

CONSTITUTION: An upper annular light source 11 which projects light upon the surface of a printed circuit board 5 from a direction perpendticular to the surface, lower annular light source 12 which projects light upon the surface of the board 5 at acute angles from all sides of the board 5, video camera 10 which picks up the optical image of a soldered joint from a direction perpendicular to the surface of the board 5, and mechanical vision processor 16 which measures the values of prescribed attributes of the optical image, compares the measured values with reference values previously set against each attribute, and detects the defect of the soldered joint based on the compared results.