A head unit includes a common flow path, one or more recording heads, and a joint mechanism. The common flow path includes a liquid supply path through which one or more types of liquid including ink pass. The recording head is attachable to and detachable from the common flow path and has nozzles that discharge ink. The joint mechanism connects the liquid supply path and the liquid supply port of the recording head. The joint mechanism includes a first on-off valve and a coupling member. The first on-off valve is fixed to the common flow path and opens/closes the liquid supply path. The coupling member couples the first on-off valve and the liquid supply port. The coupling member is movable between a coupling position where the coupling member is coupled to the first on-off valve and a retracted position where the coupling member is retracted from the coupling position.