A valve timing adjusting apparatus includes a housing, a vane rotor, and a fluid path arrangement. The fluid path arrangement is provided inside the housing. The fluid path arrangement opens to air outside the housing. The fluid path arrangement is communicated with a specific fluid chamber that is one of an advance fluid chamber and a retard fluid chamber defined within the housing. A rotational phase of the vane rotor relative to the housing is changed in one of advance and retard directions when hydraulic oil is introduced into the specific fluid chamber. The valve timing adjusting apparatus controls the fluid path arrangement to be opened and closed.