Considering a case where a patient with whiplash syndrome can sleep safely, it is when the patient is sleeping at an appropriate orientation, whereby if a pillow enabling sleep while maintaining an appropriate orientation exists, a sick person can sleep peacefully, and furthermore, the pillow may be useful in treating the whiplash syndrome. A pillow enabling the patient with whiplash syndrome to sleep peacefully is thus developed.A pillow 1 of the present invention has a deformable pillow body 2 including an upper surface cloth 21 and a lower surface cloth 22 having an edge cloth 23 as a boundary, formed with a head depression part 4 including a bottom surface 41 at a position depressed from the upper surface cloth 21 to the lower surface cloth 22 of the pillow body 2, and a groove part 6 extending from the head depression part 4 to the edge cloth 23 of the pillow body 2 and being formed by joining the upper surface cloth 21 to the lower surface cloth 22.