PURPOSE: To provide a head rest which cant easily be attached to/detached from various seat backs of different thicknesses by composing a support body of a front member and a back member which are vertically or laterally overlapped with each other at an upper part, and providing a fixing means for fixing these at a lower end part of a support pole.

CONSTITUTION: A head rest 1 is provided with a support body 3 to hold an upper part of a seat back 2 on the front and the back, a support pole 4 connected to the upper part of the support body 3, and a pad 5. The support body 3 is composed of a front member 6 and a back member 7 forming a pair which are combined with each other at the upper part, and plural positioning holes 8, 9 are provided at their upper parts to be vertically combined with each other to be positioned to each other. A fixing means 10 is provided to fix the front member 6 and the back member 7 at a lower part of the support pole 4, so the fixing means 10 fixes the front and back members 6, 7 of the support body 3 to each other, and fastens a lower end part of the support pole 4 to the support body 3 strongly. In addition, a bolt 13 is inserted to increase connection strength of the front and the back members 6, 7.