1. An FPGA configuration device, connected to an FPGA and a memory, for configuring said FPGA by using configuration data stored in said memory, comprising: a read operation control unit which performs control to read configuration data from said FPGA; a configuration data transfer unit which transfers said configuration data read out of said FPGA to said memory; and a write completion detection unit which detects completion of writing said configuration data to said FPGA, wherein reading out of said configuration data written to said FPGA and writing of said configuration data to said memory is initiated when the writing of said configuration data to said FPGA is completed.