A biometric information input device comprising: biometric information collection means (10, 31) for reading a relatively-moving living body site and successively collecting a plurality of partial images of said living body site as biometric information; movement direction detection means for detecting a movement direction of said living body site with respect to said biometric information collection means (10, 31) based on said biometric information collected by said biometric information collection means (10, 31); coordinate conversion means for performing a coordinate conversion on said biometric information collected by said biometric information collection means (10, 31) to thereby provide coordinate-converted biometric information; and biometric information display means (15, 81) for displaying a biometric information image of the living body site from the biometric information coordinate-converted by said coordinate conversion means; characterised in that: the coordinate conversion means is operable to perform said coordinate conversion using said movement direction detected by said movement direction detection means such that said movement direction becomes a vertical and downward direction with respect to the displayed image being upright, so that the biometric information display means (15, 81) thereby displays the image as upright; and wherein the device further comprises movement direction search range reduction means for, when the same movement directions have been successively detected by said movement direction detection means, reducing a movement direction search range defined as a range over which said movement direction detection means detects said movement direction to a predetermined range including said detected movement directions. biometric information collection means (10, 31) for reading a relatively-moving living body site and successively collecting a plurality of partial images of said living body site as biometric information; movement direction detection means for detecting a movement direction of said living body site with respect to said biometric information collection means (10, 31) based on said biometric information collected by said biometric information collection means (10, 31); coordinate conversion means for performing a coordinate conversion on said biometric information collected by said biometric information collection means (10, 31) to thereby provide coordinate-converted biometric information; and biometric information display means (15, 81) for displaying a biometric information image of the living body site from the biometric information coordinate-converted by said coordinate conversion means; characterised in that: the coordinate conversion means is operable to perform said coordinate conversion using said movement direction detected by said movement direction detection means such that said movement direction becomes a vertical and downward direction with respect to the displayed image being upright, so that the biometric information display means (15, 81) thereby displays the image as upright; and wherein the device further comprises movement direction search range reduction means for, when the same movement directions have been successively detected by said movement direction detection means, reducing a movement direction search range defined as a range over which said movement direction detection means detects said movement direction to a predetermined range including said detected movement directions. the coordinate conversion means is operable to perform said coordinate conversion using said movement direction detected by said movement direction detection means such that said movement direction becomes a vertical and downward direction with respect to the displayed image being upright, so that the biometric information display means (15, 81) thereby displays the image as upright; and wherein the device further comprises movement direction search range reduction means for, when the same movement directions have been successively detected by said movement direction detection means, reducing a movement direction search range defined as a range over which said movement direction detection means detects said movement direction to a predetermined range including said detected movement directions.