To cause a new data file to be surely recorded in a recording medium in a short time without losing an existing data file.

In a measurement result recording device, when a file having a temporary file name is not recorded in "any one of directories" in a memory card 7, a process A is executed in which the temporary file name is determined as a formal file name; and when a file having the temporary file name is recorded in "any one of directories", a process B is executed in which the temporary file name is renamed, and besides, as to a file whose file name is stored in a file name storage area defined in a storage part 6, the file name in the file name storage area and the temporary file name are compared with each other, and as to a file whose file name is not stored in the file name storage area, a file name determined on the basis of file name information read out of the memory card 7 and the temporary file name are compared with each other, so as to assess whether or not a file having the temporary file name is recorded.