Semiconductor pressure sensor and manufacturing method therefor

A semiconductor pressure sensor comprising:

• a first silicon substrate;
• a first silicon oxide film provided on the first silicon substrate and forming a closed space together with the first silicon substrate;
• a second silicon substrate provided on the first silicon oxide film;
• a gauge resistor provided on a surface layer of a surface of the second silicon substrate opposite to a surface on which the first silicon oxide film is provided at a position overlapping with the closed space in a plan view;
• a first electrode electrically connected to one end of the gauge resistor;
• and
• a second electrode electrically connected to another end of the gauge resistor,
• wherein the first silicon oxide film includes:
• a thick film portion having one surface in contact with the first silicon substrate and another surface in contact with the second silicon substrate;
• and
• a first thin film portion having one surface facing the first silicon substrate across the closed space and another surface in contact with the second silicon substrate,
• such that the thick film portion and the first thin film portion are parts of the first silicon oxide film.