To provide a pillow cover attaching device eliminating a risk that a pillow slips down even when a bed is inclined, and facilitating using a pillow cover twice by being reversed.

A pillow cover attaching device includes a pillow cover 10 and a holder A, and the holder A is constituted of an L-shaped member formed of a vertical plate 2 and a horizontal plate 3, and a T-shaped member provided with a hanging plate 7 at the center of a horizontally long material 6, in which the hanging plate is vertically adjustably fixed in close contact with the vertical plate 2 of the L-shaped member. An attaching cloth 12 for fixing the horizontally long material 6 is provided on the back surface of the pillow cover 10, and the edge part of a bed 15 is held between the pillow cover 10 and the holder A.