A finger contact detecting apparatus, which detects a finger being swept on a fingerprint sensor of the finger contact detecting apparatus, the finger contact detecting apparatus including, a pixel data averaging unit calculating an average value of pixel data collected by the fingerprint sensor; a deviation adding unit calculating, based on the average value and respective pixel data of predetermined pixels obtained by the fingerprint sensor, a summation of deviations of the respective pixel data of the predetermined pixels; and a finger contact detecting unit determining whether the finger is separated from the fingerprint sensor based on the summation of deviations and a predetermined threshold value.