To provide a marking inspection apparatus capable of performing a total inspection.

In this apparatus, a slit light 31 is applied in a line from a laser device 32 in the width direction of a work 11 while moving a stage 63, and the slit light applied to a marked surface 2 of the workpiece 11 is imaged by a CCD camera 41 and taken into a control unit 71. A movement position of the stage 63 and an imaged position 101 and received light intensity of the slit light 31 are associated with one another and stored in a storage device, and also three-dimensional information of the marked surface 2 is computed based on the movement position of the stage 63 and the imaged position 101 and stored in the storage device. After smoothing the three-dimensional information according to the receiving light intensity, a change in depth data which the three-dimensional information has is converted into the change in the density, which thickens in proportion to the depth, to generate a density image 111, and this density image is stored in the storage device and displayed in a monitor.