The polytetrafluoroethylene (PTFE) porous membrane according to present disclosure has an average fibril length of 50 [mu]m or more, an average node length that is at least five times of the average fibril length, and an average node area ratio of 5% or less. The PTFE porous membrane according to the present disclosure, when attached as a waterproof breathable membrane to a housing of an electrical product, an electrical component, or the like, can allow water vapor retained in the housing to be more quickly discharged out of the housing.