To improve the usability during biometric authentication, a biometric authentication device (100) includes: an image sensing section (101) configured to capture a biometric authentication image of a part of a living body； a display section (107) configured to display a guide image among a plurality of guide images for aligning the part of the living body and the image sensing section (101) with each other in order for the image sensing section (101) to capture the biometric authentication image； and a control section (110) configured to carry out authentication on a basis of the biometric authentication image, the control section (110) being configured to cause the display section (107) to display one of the plurality of guide images on a basis of at least either (i) an authentication accuracy corresponding to application software configured to operate in accordance with a result of the authentication or (ii) image sensing environment information related to the capturing, the plurality of guide images at least including (i) a first guide image for aligning the part of the living body and the image sensing section with each other at such respective positions that the part of the living body and the image sensing section are separated from each other by a first distance and (ii) a second guide image for aligning the part of the living body and the image sensing section with each other at such respective positions that the part of the living body and the image sensing section are separated from each other by a second distance smaller than the first distance.
