To realize an integrated pressure-difference flowmeter, having simple structure in which the measurement accuracy can be enhanced by suppressing the effect of pulsating component of a fluid to be measured.

A fluid to be measured flows from a high-pressure side pressure conduction pipe 102 to a low-pressure side pressure conduction pipe 104 through the joint 171 and the restricting mechanism section 172 of a pressure difference generator. The restricting mechanism section 172 of the pressure-difference generator comprises a thin-metal tube 172 serving as an absorber of the pulsation energy of the fluid to be measured. This structure suppresses the pulsating component of a differential pressure to be detected, resulting from pulsation of the fluid to be measured, thus enhancing the measurement accuracy.