To provide an eggshell cutting device capable of cutting a part of an eggshell in a circular shape having the optional size without practically causing a crack.

This eggshell cutting device is characterized by having a circular cutter 4 of a circular saw shape, a cutter rotating part 3 for rotating the circular cutter 4 at a high speed, an egg holder 10 for fixing an egg, an egg holder rotating part 9 for rotating the egg holder 10 at a low speed, and a cutting action adjusting part (a movable bracket 8) for changeably constituting a cutting relative position between the circular cutter 4 of the cutter rotating part 3 and the egg T fixed to the egg holder 10. A part of the eggshell of the egg 5 is cut open by rotating by pushing the circular cutter 4 against a head top part of the egg.