A substrate inspection apparatus includes a mounting table, an inspection unit, a temperature control unit and a medium channel. The mounting table mounts thereon a substrate on which a semiconductor device is formed. The inspection unit inspects electrical characteristics of the semiconductor device on the mounted substrate. The temperature control unit controls a temperature of the mounting table. The medium channel passes through the mounting table. The temperature control unit includes a high-temperature medium supply unit supplies a high-temperature medium to the medium channel, a low-temperature medium supply unit supplies a low-temperature medium to the medium channel and a medium mixing unit mixes the high-temperature medium and the low-temperature medium which are supplied to the medium channel.