A neutral hold device for a hydrostatic continuously variable speed change device having a trunnion shaft, comprising a first member which rotates integrally with the trunnion shaft and in which a cam having a concave part is formed; a second member that pivots about a support shaft provided parallel to the trunnion shaft, and that is provided with a cam follower for engaging with the cam; a spring for urging the cam follower against the cam so that the trunnion shaft is retained in a neutral position by the cam follower being positioned in a set position of the cam by the urging of the spring; and auxiliary urging means for generating an auxiliary urging force for urging the trunnion shaft toward the neutral position while the trunnion shaft is positioned in a proximate region of the neutral position set in advance.