A honeycomb structure defect inspection device 1 includes a defect detection means 2 for introducing a detection medium 21 into cells 12 from one end face 15a of a honeycomb structure while applying a pressure for passing the medium 21 through cells 12 and detecting the medium 21 passed through cells 12 and discharged from the other end face 15b to identify a cell 12 having the defect in its partition wall 13 from the dynamic state of the detection medium 21; and a covering means of an outer peripheral wall of the honeycomb structure so as to maintain the pressure to cause the medium 21 to flow toward the other end face 15b while suppressing the leakage of the pressure from the outer peripheral wall 14 and to sufficiently keep the discharge of the medium 21 from cells having no defect in its partition walls 13.
