A face detection apparatus and a face detection method thereof are provided. The face detection apparatus includes a rectangle integral image unit, a feature mapping unit and a cascade and score unit. The rectangle integral image unit provides a rectangle integral image according to an original image. The feature mapping unit determines a face candidate region according to rectangular face feature templates, and calculates feature values of the rectangular face feature templates according to the rectangle integral image. The cascade and score unit judges whether the face candidate region conforms to cascade conditions or not, and gives the face candidate region a score according to the feature values when the face candidate region conforms to the cascade conditions. The face candidate region is a non-face region if the score of the face candidate region is lower than a threshold value.