There is disclosed an inspection device (110) of a plugged honeycomb structure in which a plugged honeycomb structure (31) is an inspection target, and the inspection device comprises a light source (1) which illuminates one end face (35) of the plugged honeycomb structure (31) as the inspection target; a camera-side lens (2) which condenses light emitted from the light source (1) to the one end face (35), transmitted through plugged portions of the plugged honeycomb structure (31) and radiated from the other end face (36); a camera (3) which receives the light condensed by the camera-side lens (2); and an image processor (4) which processes an image of the light received by the camera (4) to display the contrast of the light transmitted through the plugged portions of the plugged honeycomb structure (31). The provided inspection device of the plugged honeycomb structure can inspect the depth and defect of the plugged portions in a non-contact manner in a short time period.