A probe including a catheter sheath, a shaft inserted inside the catheter sheath, and an attachment portion detachably attached to a rotational drive unit, wherein the attachment portion includes an isolation member isolating the inside of the attachment portion into a first area in which a member for transmitting the drive force generated by the rotational drive unit to the shaft is rotatably held and a second area in which the catheter sheath is fixedly held the isolation member includes: an insertion hole through which the shaft is inserted between the first area and the second area and an ejection hole provided in a surface to which an end portion on the rotational drive unit side of the catheter sheath is connected and which is approximately perpendicular to the rotation axis of the shaft and the ejection hole defines a flow path extending to the outside of the isolation member.
