For personal authentication using biometric information, to allow for unfailing authentication without increasing verification time even for an authentication object that is not supported only by a minutia matching method, the present invention provides a biometric information authentication device comprising: a first verifying section for verifying first to-be-verified data against first registration data registered preliminarily using a minutia matching method; a second verifying section for verifying second to-be-verified data against second registration data registered preliminarily using a pattern matching method; and a determining section for comparing match degree, which is obtained as a result of verification by the first verifying section, with a first threshold value and a second threshold value to allow the second verifying section to perform verification in the case where the match degree is equal to or smaller than the first threshold value and equal to or larger than the second threshold value.