A pressure gauge comprising: an outer container defining an outer chamber set to a reference pressure (Pr); an inner container partitioning an inner chamber disposed in the outer container into a first inner chamber air-tightly partitioned from the outer chamber and into a second inner chamber communicating with the outer chamber ; and a tube setting the first inner chamber to a measurement pressure (Px), the inner container including: a cylindrical rigid wall portion ; first and second pressure receiving plates formed as opposing wall portions of the inner container and displaced due to a differential pressure between the reference pressure (Pr) and the measurement pressure (Px); a bellows disposed in the inner chamber surrounded by the cylindrical rigid wall portion and the first and the second pressure receiving plates so as to partition the inner chamber into the first inner chamber and into the second inner chamber , the bellows being deformable to allow displacements of the first and the second pressure receiving plates ; and a pressure detection element disposed in the second inner chamber and detecting the measurement pressure (Px) based on the displacements of the first and the second pressure receiving plates , the outer chamber and the second inner chamber being set to the reference pressure (Pr) of a high vacuum that is lower than a lower limit of the measurement pressure (Px). an outer container defining an outer chamber set to a reference pressure (Pr); an inner container partitioning an inner chamber disposed in the outer container into a first inner chamber air-tightly partitioned from the outer chamber and into a second inner chamber communicating with the outer chamber ; and a tube setting the first inner chamber to a measurement pressure (Px), the inner container including: a cylindrical rigid wall portion ; first and second pressure receiving plates formed as opposing wall portions of the inner container and displaced due to a differential pressure between the reference pressure (Pr) and the measurement pressure (Px); a bellows disposed in the inner chamber surrounded by the cylindrical rigid wall portion and the first and the second pressure receiving plates so as to partition the inner chamber into the first inner chamber and into the second inner chamber , the bellows being deformable to allow displacements of the first and the second pressure receiving plates ; and a pressure detection element disposed in the second inner chamber and detecting the measurement pressure (Px) based on the displacements of the first and the second pressure receiving plates , the outer chamber and the second inner chamber being set to the reference pressure (Pr) of a high vacuum that is lower than a lower limit of the measurement pressure (Px). a cylindrical rigid wall portion ; first and second pressure receiving plates formed as opposing wall portions of the inner container and displaced due to a differential pressure between the reference pressure (Pr) and the measurement pressure (Px); a bellows disposed in the inner chamber surrounded by the cylindrical rigid wall portion and the first and the second pressure receiving plates so as to partition the inner chamber into the first inner chamber and into the second inner chamber , the bellows being deformable to allow displacements of the first and the second pressure receiving plates ; and a pressure detection element disposed in the second inner chamber and detecting the measurement pressure (Px) based on the displacements of the first and the second pressure receiving plates , the outer chamber and the second inner chamber being set to the reference pressure (Pr) of a high vacuum that is lower than a lower limit of the measurement pressure (Px). <EOS>