Valve open/close timing control device

Provided is a valve open/close timing control device including, a drive-side rotating body (1), a driven-side rotating body (2), a fluid pressure chamber (4), a partition portion (22), a fluid control valve part, a first locking mechanism (6) which is capable of restraining a relative rotational phase of the driven-side rotating body (2) relative to the drive-side rotating body (1) at a first predetermined phase between a most retarded angle phase and a most advanced angle phase, and a second locking mechanism (7) which is capable of restraining the relative rotational phase at a second predetermined phase on a more retarded angle side than the first predetermined phase, in which the relative rotational phase is changed to the first predetermined phase when a shift lever position is changed to a parking range.