A high pressure canister unit includes: plural arrayed canister bodies, each canister body being formed in a circular cylinder shape, and including an opening at at least one end portion in its axial direction; a coupling member that is connected to the opening of each of the canister bodies and that couples the plural canister bodies together, and the coupling member including a flow path placing interiors of the canister bodies in communication with each other; a box-shaped case that is configured to house the plural canister bodies and the coupling member, the case including a through hole; and a leader tube that is provided to the coupling member, that leads out to an exterior of the case through the through hole of the case, and to which a valve capable of opening and closing the flow path is attached.