Diaphragm suppressing pressure sensor

A pressure sensor comprising:

• a cylindrical casing extending in an axial direction;
• a diaphragm which is joined to a distal end side of the casing, expands in a direction that intersects an axis of the casing, and which is deformed in accordance with a pressure received on the distal end side;
• and
• a sensor section which is disposed inside the casing and which outputs an electric signal that corresponds to the deformation of the diaphragm,
• wherein the diaphragm includes a plate-shaped base part and three or more protruding parts which protrude from a surface on the distal end side of the base part toward the distal end side and which are set apart from each other, and
• wherein relationships 0.05T≤H≤2.5T and 0.05≤(S2/S1)≤0.8 are satisfied, when T is a thickness of the base part, H is a length in the axial direction of the protruding parts, S1 is an area of a base distal end surface that would be the surface on the distal end side of the base part if the protruding parts were not present, and S2 is a total area of protruding distal end surfaces that are surfaces on the distal end side of the three or more protruding parts.