A welded portion inspection apparatus for inspecting a welding state of a welded portion formed at the time when a plurality of workpieces (W1, W2) is welded, the welded portion inspection apparatus comprising: a radiation portion configured so as to radiate a welding laser beam along a welding locus set in the workpieces (W1, W2) so as to weld the workpieces (W1, W2), or so as to radiate an inspection laser beam along a scanning locus set in a molten pool of the workpieces (W1, W2) that are molten by a welding laser beam; a light-receiving portion for receiving a returned light beam including at least one of reflection light of the welding laser beam or the inspection laser beam radiated by the radiation portion, the reflection light being reflected from the molten pool of the workpieces (W1, W2), vapor light caused due to melting and evaporation of the workpieces (W1, W2), and thermal radiation light emitted from the molten pool of the workpieces (W1, W2); and an inspection portion for inspecting a welding state of a welded portion of the workpieces (W1, W2) based on an intensity of a returned light beam received by the light-receiving portion in a first region inside the molten pool of the workpieces (W1, W2) which is relatively close to a given point and an intensity of a returned light beam received by the light-receiving portion in a second region inside the molten pool of the workpieces (W1, W2) which is relatively spaced from the given point; and the welded portion inspection apparatus being characterized in that: the inspection portion is configured so as to inspect the welding state of the welded portion of the workpieces (W1, W2) based on a ratio between the intensity of the returned light beam received by the light-receiving portion in the first region and the intensity of the returned light beam received by the light-receiving portion in the second region. a radiation portion configured so as to radiate a welding laser beam along a welding locus set in the workpieces (W1, W2) so as to weld the workpieces (W1, W2), or so as to radiate an inspection laser beam along a scanning locus set in a molten pool of the workpieces (W1, W2) that are molten by a welding laser beam; a light-receiving portion for receiving a returned light beam including at least one of reflection light of the welding laser beam or the inspection laser beam radiated by the radiation portion, the reflection light being reflected from the molten pool of the workpieces (W1, W2), vapor light caused due to melting and evaporation of the workpieces (W1, W2), and thermal radiation light emitted from the molten pool of the workpieces (W1, W2); and an inspection portion for inspecting a welding state of a welded portion of the workpieces (W1, W2) based on an intensity of a returned light beam received by the light-receiving portion in a first region inside the molten pool of the workpieces (W1, W2) which is relatively close to a given point and an intensity of a returned light beam received by the light-receiving portion in a second region inside the molten pool of the workpieces (W1, W2) which is relatively spaced from the given point; and the inspection portion is configured so as to inspect the welding state of the welded portion of the workpieces (W1, W2) based on a ratio between the intensity of the returned light beam received by the light-receiving portion in the first region and the intensity of the returned light beam received by the light-receiving portion in the second region.