Inertial sensor

An inertial sensor includes a sensing portion (10) having a weight (12) supported by beams (13), the weight (12) being a movable portion, and a weight stopper (16) that limits a movable range of the weight (12), the weight stopper (16) being arranged in a vicinity of the weight (12) with a given clearance and being a part of a substrate for the inertial sensor processed with MEMS techniques.