PROBLEM TO BE SOLVED: To provide an egg diameter measuring device capable of highly accurately measuring an egg diameter by simple processing.SOLUTION: This is an egg diameter measuring device for measuring the diameter of eggs E while transporting them, including a lined-up transportation part 3 which transports eggs E, with the major axes made horizontal and also orthogonal to the lined-up transporting direction X of the eggs E a light projection part 6 which projects a spotlight 5 to the body part of eggs E from the major axes direction of the eggs E transported by the lined-up transportation part 3 and from nearly the vertical direction of the lined-up transporting direction X a light receiving part 7 which receives the reflected light of the spotlight 5 projected to the body part of the eggs E by the light projection part 6 and a calculation part which calculates the diameter of the eggs E based on the reflected light received by the light receiving part 7. According to the diameter measuring device of the invention, the diameter of the eggs E can be measured with high accuracy by simple processing.
