A biometric authentication device includes: a memory; and a processor coupled to the memory and the processor configured to execute a process, the process comprising: acquiring a plurality of sets of palm images taken under different illumination conditions of an illumination source from one another in obtaining images of a palm with light emitted from the illumination source; adjusting a time interval at which the imaging device acquires the image sets, in accordance with a condition for imaging the palm; extracting a biological feature from each of the image sets; and comparing each biological feature extracted by the extracting with a biological feature registered in advance.