Abstract: An automatic brake shoe measuring apparatus for rolling stock automatically measures the thickness of brake shoes of a vehicle and automatically detecting the presence or absence of damage during travel. The automatic measuring apparatus includes: a camera unit including a monitor camera for photographing brake shoes of a vehicle during travel and outputting an image signal, an image memory for storing the image signal, and a trigger detector for outputting a trigger signal to thereby store an image signal representing an image of a specific brake shoe of the vehicle; and an image processing unit including an extraction means for extracting the specific brake shoe in accordance with the image signal stored in the image memory and transferred from the camera unit, an arithmetic means for calculating the thickness of the specific brake shoe extracted by the extraction means, and a display means for displaying the thickness of the specific brake shoe calculated out by the arithmetic means.