To provide a dental unit which has a simple structure, has high reliability, and prevents collision between a patient chair and a doctor unit.

The dental unit includes: a base table 20; a patient chair 10; a doctor unit 30 provided with a first arm 40, a second arm 45, and a working table 31 placing instruments used for treatment; and an interference detection device 50 for prohibiting rise/fall and tilting/standing of the patient chair when there is a possibility for at least a part of the doctor unit to enter a range of the rise/fall and tilting/standing of the patient chair. The interference detection device includes: a detected means 55 for changing a physical amount with a rotation amount of the first arm and a rotation amount of the second arm as an integrated value; a detecting means 56 for detecting the physical amount of the detected means; and a stop command means 166 which is connected to the detecting means and provided so as to prohibit rise/fall and tilting/standing of the patient chair on the basis of information from the detecting means.