The semiconductor device comprises a semiconductor layer 18 formed on an insulation layer 16, a gate electrode 22 formed on the semiconductor layer with a gate insulation film 20 formed therebetween, a sourcedrain region 24 formed on the semiconductor layer on both sides of the gate electrode, and a semiconductor region 14 buried in the insulation layer 16 in a region below the gate electrode. Each probe is successively selected by a switch circuit under control of a control section and connected to a property calculation section. The amount of digital video data corresponding to the access time for accessing the recording areas of the optical disk are reproduced from the optical disk at a speed higher than the bit rate at which the video data is input or output and stored in the buffer memory.