In a window regulator which moves a slider base, slidable along a guide rail, via a pair of wires, the slider base includes: a guide portion which is fitted to the guide rail to be movable in the longitudinal direction thereof; first and second wire engaging portions with which ends of the wires are engaged, respectively; and first and second force application portions which receive a force in a moving direction of the slider base from the wires, and the guide portion is positioned in at least one of the areas between the first force application portion and the first wire engaging portion and between the second force application portion and the second wire engaging portion in the widthwise direction of the guide rail. This makes it possible to obtain a window regulator which is superior in smoothness of operation and operating efficiency of the slider base.