An apparatus for picking up objects including a robot for picking up an object, at least one part of the object having a curved shape, having a storing means for storing a gray gradient distribution model of the object, a recognizing means for recognizing a gray image of the object, a gradient extracting means for extracting a gray gradient distribution from the gray image recognized by the recognizing means, an object detecting means for detecting a position or position posture of the object in the gray image in accordance with the gray gradient distribution extracted by the gradient extracting means and the gray gradient distribution model stored by the storing means, a detection information converting means for converting information of the position or position posture detected by the object detecting means into information of position or position posture in a coordinate system regarding the robot; and a robot moving means for moving the robot to the position or position posture converted by the detection information converting means to pick up the object. Thus, the object having a curved shape can be detected and picked up in a reasonably short period of time.