A hatching egg inspection apparatus includes a loader unit, an inspection unit for determining the viability or the like as to whether a hatching egg is an unfertilized egg or a growth-stopping egg, a rejection unit for rejecting a hatching egg determined to be an unfertilized egg or the like, and an unloader unit for sending a hatching egg toward the next step. The inspection unit is provided with a light emitting unit for emitting prescribed light toward the hatching egg, a cap attachment unit through which the light having been emitted to the hatching egg and having transmitted through the hatching egg passes, and a light receiving unit for receiving the light that has passed through the cap attachment unit. The cap attachment unit includes a cylindrical cap coming into contact with the hatching egg, and a plate to which the cap is attached.
