A difference degree evaluation device includes a signal acquisition unit which acquires at least two signals which are objects of matching, a memory unit which stores one of the two signals, which are acquired by the signal acquisition unit, as a reference signal, and stores the other of the two signals as an object signal, a sample extraction unit which extracts sample points in a predetermined block from the reference signal that is stored in the memory unit, and extracts sample points corresponding to the sample points of the reference signal from the object signal, and an arithmetic process unit which finds absolute difference values between the sample points of the reference signal and the sample points of the object signal, which are extracted by the sample extraction unit, and calculates a maximum value of the absolute difference values as an evaluation value.