An inspection device inspects a display for defects. The display includes a power supply, a circuit board having a stabilizer to stabilize the power supply, a display panel which is electrically connected to the circuit board and has a first electrode, and an input sensor which is disposed on the display panel and has a second electrode. The inspection logic measures a value of capacitance between the first electrode and the second electrode of the display, and includes a frequency setter that sets a driving frequency of the second electrode to a frequency in a predetermined range.