An apparatus structure and measurement method are provided to retain high precision and high reliability of a semiconductor mechanical quantity measuring apparatus which senses a mechanical quantity and transmits measured information wirelessly. As to a silicon substrate of the semiconductor mechanical quantity measuring apparatus, for example, a ratio of a substrate thickness to a substrate length along a measurement direction is set small, and a ratio of a substrate thickness to a substrate length along a direction perpendicular to the measurement direction is set small. The apparatus upper surface is covered with a protective member. It is possible to measure a strain along a particular direction and realize mechanical quantity measurement with less error and high precision. An impact resistance and environment resistance of the apparatus itself can be improved.