Provided is a compensating device for a received data can be used in a wide application by a single apparatus for various wiring configurations and transmission media. The compensating device provided between a receiver circuit in a physical layer and a processing device utilizing the received data and including a plurality of preprocessing units provided in parallel with each other on an output side of the receiver circuit and each having a filtering function and a sampling function which have different characteristics from each other, a plurality of check units each provided in a next stage of the preprocessing unit and serving to execute a reliability check of the received data in accordance with a frame format of a protocol, a plurality of buffer units each provided in the next stage of the check unit and serving to store the data processed by the check unit, and a data selector for monitoring check results in the check units and selecting and outputting the data of the buffer units having a check result of OK.