In this paper, we present a robust pose estimation method of a human body hidden with a cover. Our goal is an automatically monitoring system of sleeping human using noncontact and noninvasive sensors for elderly care. We propose a new method for robust human pose estimation from a single depth image using human body shape model constructed by normal vector information. This shape model is able to represent shapes of rough body, and is effective in robust pose estimation for a person who placed futon and blanket. In our method, first, head position is detected from a depth image using SVM. Then, body region is detected by comparing human body shape model. Head position is used as initial position of body region detecting. Body region is composed of many small rectangles. Next, body region is divided into three body parts by distance between parts. Finally, each part pose is determined by a linear estimation using point clouds of right and left of the rectangle in each body region.