To reliably detect connection of a cable by comparing the voltage generated on one end of a transmission track of a pair of transmission tracks to which a pulse signal for inspection is supplied with a reference voltage.

A cable inspection device includes a pulse generation part 2 which generates the pulse signal Sp0 for inspection, a transmission part 3 which generates the pulse signal Sp1 for inspection by amplifying the pulse signal Sp1 for inspection and supplies the pulse signal Sp1 for inspection to the transmission track 12 from one end of the transmission track 12 in a LAN cable 11 connected to a connector 6 for inspection, and a processing part 7 which compares a threshold voltage Vth1 of which voltage is defined as a higher voltage than that of the pulse signal Sp1 for inspection on one end of the transmission track 12 when the LAN cable 11 is connected to the connector 6 for inspection with the voltage of a voltage signal Sin generated on one end of the transmission track 12 and which determines that the LAN cable should be connected to the connector 6 for inspection when the voltage of the voltage signal Sin is above the threshold voltage Vth1 at the point late in starting of supply of the pulse signal Sp1 for inspection.