Abstract: An electrostatic capacitive sensor able to detect a first electrostatic capacitance and a second electrostatic capacitance, comprising: a member wherein is formed a movable diaphragm that has electrical conductivity; a thin-film electrode that forms a first electrostatic capacitance with the diaphragm; a thin-film electrode that forms a second electrostatic capacitance with the diaphragm; an upper member that is provided so as to form a space between itself and the top face of the diaphragm; and a tower member that is provided so as to form a second space between itself and the bottom face of the diaphragm; wherein: a gas is filled into the space and another gas, which has a coefficient of thermal expansion different from that of the gas, is filled into the second space.