To provide a mouth cleaning instrument which does not cause a cross infection when it is used for a plurality of patients and can be safely used.

The mouth cleaning instrument 1 including a cleaning head 2 having a cleaning solution supply pipe 3 and a cleaning solution sucking pipe 4, includes a grip 6 having a cleaning solution supply pipe connecting portion 69 to be connected to the cleaning solution supply pipe 3 and a cleaning solution sucking pipe connecting portion 64 to be connected to the cleaning solution sucking pipe 4, and a cleaning member 5 provided at the tip of the cleaning head 2 and can prevent the cleaning solution supply pipe connecting portion end 69a from getting contaminated and can reduce the possibility of causing a cross infection by being provided with a cleaning solution supply pipe connecting portion end 69a and a cleaning solution sucking pipe connecting portion end 64a outside the same plane or on a discontinuous plane and can sufficiently secure a sanitary safeness without the contamination of a poured solution through the contact of a sucked solution containing various bacteria with the cleaning solution supply pipe connecting portion end 69a of the grip 6 when the cleaning head 2 is attached or detached and without the infection of a previous patient's bacteria through the poured solution of a subsequent patient when applying mouth cleaning to a plurality of patients.