The invention provides a semiconductor acceleration sensor which is small in size, light in weight, simple in manufacture, low in manufacturing cost, and high in accuracy, and which, with a switch-on time set to a predetermined value, is stable in operation.In a semiconductor acceleration sensor in which a central board 1 having a central contact section 11, and outside boards 2 at least one of which has an outside contact section 21 are stacked; the central board 1 has a weight 12 near the central contact section 11, and the outside board 2 having the outside contact section 21 has a weight confronting section 11 which confronts with the weight 12, for squeezed damping effect.