To provide a diaphragm seal type pressure measuring device which reduces leakage amounts of liquids put inside a first and a second connecting pipe and sealed, when the first and second connecting pipes are separated at an attaching/detaching part, by providing a valve in at least one of the first connecting pipe to be connected to the pressure measuring instrument and the second connecting pipe to be connected to a diaphragm seal.

In the diaphragm seal type pressure measuring device provided with the first connecting pipe containing the sealed liquid to be connected to the pressure measuring instrument, the second connecting pipe containing the sealed liquid to be connected to the diaphragm seal, and the attaching/detaching part for connecting or separating the first connecting pipe and the second connecting pipe to or from each other, at least one of the first and second connecting pipes has a valve.