To provide a treatment unit and a client unit forming a shielded treatment space so as to conceal treatment instruments to be used from a patient approaching a dental treatment chair and so as to keep treatment circumstances out of another person's sight.

A treatment unit 20 and a client unit 30 are arranged in the vicinity of a treatment position (a head 11) of a dental treatment chair 10 and cooperate mutually so as to form a treatment space and a consulting space in dental treatment. A treatment unit 20 is provided with a supporting column 21, a doctor table 22 connected rotationally around the supporting column, and a partition 23 having a film viewer, a monitor and the like on the side facing a doctor. The client unit 30 is also provided with a supporting column 31, a spittoon 32 connected around the supporting column 31 rotationally, and a partition 33 having a film view, a monitor and the like.