To provide an ultra-precise minute differential pressure measuring device capable of precisely and continuously measuring a minute differential pressure and significantly reducing the manufacturing cost with a simple structure by transmitting the minute differential pressure to an electronic weigher & pressure converter without a mechanical sliding part.

This device comprises a device body 1 having a space part in the inner part, a pressure receiving plate 3 disposed in the internal space of the device body 1 to air-tightly divide the internal space to a lower pace 7 and an upper space 8, the electronic weigher & pressure converter 2 disposed in the lower space 7 to support and fix the pressure receiving plate 3 thereon, and a liquid sealing part R for liquid-tightly sealing the peripheral part of the pressure receiving plate 3 to retain the air-tightness between the lower space 7 and the upper space 8. In this device, the minute differential pressure between the pressure P1 in the upper space 8 and the pressure P2 in the lower space 7 is measured by the electronic weigher & pressure converter 2 through the pressure receiving plate 3.