Measuring device and measuring system

A measuring device comprising:

• a first sensor provided on a surface of an object to be measured,
• a case provided to ensure that the first sensor is located between the case and the object to be measured,
• an elastic body interposed between the case and the object to be measured, and
• a processing circuit which is provided inside the case and processes the output signal of the first sensor, wherein
• the first sensor includes a strain sensor,
• the strain sensor is a chip comprising a thin film piezoelectric element, the chip is mounted on a flexible substrate by wire bonding, and the flexible substrate has a wire connection part to which a wire extending to the outside is connected, and
• a metal foil having a thickness of 20 μm or less is formed on a surface of the flexible substrate on a side opposite from the chip, and the metal foil includes at least a part corresponding to the direct back side part of the chip.