An endoscopic fluid passage changeover valve unit includes a seal member blocking a communication between a first upstream-side fluid passage and a first space portion in a first input mode and allowing the communication between the first upstream-side fluid passage and the first space portion in a second input mode in which a shaft has been rotated a predetermined rotation angle around a movement axis from the first input mode. The endoscopic fluid passage changeover valve unit includes a first fluid passage open-or-close portion provided between the first space portion and a second space portion and supplying, to the second space portion, a first fluid that has been supplied to the first space portion through the first upstream-side fluid passage when the opening of a communication passage is blocked in the second input mode.
