An evoked potential measuring apparatus includes: an evoked potential acquiring section which is configured to acquire a plurality of evoked potential waveforms from a subj ect in response to stimulation； an average processing section which is configured to arithmetically average the plurality of evoked potential waveforms to acquire an average waveform； a first statistical value calculator which, each time a waveform set including an N (N is 2 or more) number of evoked potential waveforms is acquired, is configured to calculate a first statistical value of the waveform set； and an updation processing section which is configured to update the average waveform to eliminate a waveform set in which the first statistical value exceeds a first threshold, from the arithmetic average.
