Abstract: An X arm type window regulator includes a lift arm, a lift arm bracket, an equalizer arm, and an equalizer arm bracket. The window regulator opens and closes window glass through pivotal movement of the lift arm. The lift arm has two stress-dispersing elongated protrusions provided in respective regions which are located in the vicinity of an annular protrusion provided around a through hole formed in a central portion thereof, the regions being located on the side toward a proximal end portion of the lift arm and located toward two respective edges of the lift arm. The stress-dispersing elongated protrusions have a function of dispersing stress caused by a load imposed on the distal end portion of the lift arm.