To provide a hair brush lockingly holding a brush unit, which is slidably mounted on a brush body, to be prevented from being detached and surely preventing the brush unit from separating and falling from the brush body even if receiving a falling impact.

This hair brush is provided with the brush body 1, the brush unit 2 detachably mounted on a brush mount 3 and a lock structure lockingly fixing the brush unit 2 to be prevented from being detached. The joining faces of the brush mount 3 and the brush unit 2 can be mutually engaged via a first engagement operation approaching to/separated from each other and a second engagement operation slidingly fitted in the direction of crossing with the first engagement operation. The lock structure comprises an abutment part 45 provided in a base 40 of the brush unit 2, a lock body 46 engaged with/disengaged from the abutment part 45 and an operation body 47 releasing the lock of the lock body 46. The lock body 46 is formed of a stopper frame 48 engaged with/disengaged from the abutment part 45 and a pair of elastic arms 49 extending from the stopper frame 48 into a portal shape. The elastic deformation of the elastic arms 49 can engage/disengage the stopper frame 48 with/from the abutment part 45.