Provided is a technique for achieving improvement of usability in setting parameters. An error rate measuring apparatus includes a display unit that displays input boxes for inputting one Codeword length and one FEC Symbol length of FEC on a setting screen, and an operation unit that inputs the one Codeword length and the one FEC Symbol length to the corresponding input boxes according to a communication standard of a device under test. A graphic of one Codeword, a graphic of one FEC Symbol, and a graphic of one Codeword including an error for identifying a configuration relationship of an FEC Symbol to a Codeword of the FEC and a correspondence relationship of an FEC Symbol Error to the Codeword are displayed on the setting screen corresponding to the input box of each of the one Codeword length and the one FEC Symbol length of the FEC.