Electrostatic capacitance can be measured with high directivity in a specific direction. A sensor chip that measures the electrostatic capacitance includes a first electrode, a second electrode and a third electrode. The first electrode has a first portion. The second electrode has a second portion extended on the first portion of the first electrode, and is insulated from the first electrode within the sensor chip. The third electrode has a front face extended in a direction which intersects with the first portion of the first electrode and the second portion of the second electrode, and is provided on the first portion and the second portion. The third electrode is insulated from the first electrode and the second electrode within the sensor chip. No portion is extended from the first electrode to be positioned above the first portion.