[problem] has removable pressure sensor to provide a kind of dismountable pressure sensor and extracorporeal circulation apparatus, these devices allow to be easy and rapidly, safely the internal liquid circulation of measuring circuit passes through circuit connection. There is removable pressure sensor 30 of the invention main body 31 and pressure sensing element 40 to be arranged in ontology 31. Main body 31 includes: that there is pedestal 32 pipe to install recess 34, the pipe 11 (12,19) of one interlude is removably inserted into, to be resiliently deformed, pipe 11 (12,19), to allow the interior press liquid of 40 sensing circuit of pressure sensor in pipe 11 (12,19) The groove of bottom 34, and the therefore groove 34. in retainer pipe 11 (12,19) are installed with 33 sealed tube of lidThere is the recess portion 34 that pipe is installed to hose mounting portion the rectangular cross section of rectangular cross section and width L to be set, to be less than the pipe of outer dimension D.
