Spark plug for internal combustion engine use and method of manufacturing spark plug

An outer periphery of the tubular housing includes a parallel surface, a pressure contact surface and a connection surface. The parallel surface is formed parallel to an axial direction of the spark plug. The pressure contact surface is located closer to a tip of the spark plug and more radially inward than the parallel surface. The pressure contact surface has a tapered shape in that a diameter decreases toward the tip. The pressure contact surface is pressed against a cylinder head when installed in the internal combustion engine. The connection surface is located closer to a base of the spark plug than an extension line in a longitudinal cross-section of the spark plug parallel to the axial direction including a plug central axis. The connection surface connects an outer peripheral end of the pressure contact surface with a longitudinal end of the parallel surface.