In this work, we propose a novel computer vision based fall detection system, which could be applied for the health-care of the elderly people community. For a recorded video stream, background subtraction is firstly applied to extract the human body silhouette. Extracted silhouettes corresponding to daily activities are applied to construct a convolutional neural network, which is applied for classification of different classes of human postures (e.g., bend, stand, lie and sit) and detection of a fall event (i.e., lying posture is detected in the floor region). As far as we know, this work is the first attempt for the application of the convolutional neural network for the fall detection application. From a dataset of daily activities recorded from multiple people, we show that the proposed method both achieves higher postures classification results than the state-of-the-art classifiers and can successfully detect the fall event with a low false alarm rate.