PURPOSE: To enhance inspection efficiency and to attain to make a measuring apparatus compact, by arranging plural detectors, which can advance and retract with respect to the upper, front, rear right and left surfaces of an object to be inspected, to a main body part capable of moving along a feed line.

CONSTITUTION: A track surface 3 is provided along a feed line 1 for feeding an article to be inspected so as to be capable of moving the main body part 3 of a measuring apparatus along the feed line 1. Detectors S1, S3WS6, which are opposed to the upper, front, rear, right and left surfaces of the article to be inspected and can advance and retract, are arranged to the main body part 3 and an under surface detector S2 is arranged to the part below the feed line 1 opposed to an upper surface detector S1. By this method, the inspection of each surface is performed while the main body part 3 is moved with the move ment of the article to be inspected and, therefore, inspection efficiency is en hanced.