Data processing device, semiconductor external view inspection device, and data volume increase alleviation method

Provided is a data processing device with which, when a temporary network congestion occurs, it is possible to avoid a buffer overflow and sustain a process. When a request for retransmission of the same data with respect to a processor element from a buffer occurs continuously a prescribed number of iterations, a data processing device according to the present invention determines that it is possible that a buffer overflow occurs, and suppresses an increase in the volume of data which is accumulated in the buffer (see FIG. 1).