A fuel vapor processing apparatus includes a vapor path connecting an adsorbent canister to a tank, where a valve is disposed in the vapor path and comprises a body and a seat, and a control unit configured to detect a movement distance of the body from the seat as a valve movement distance at a valve opening start position. This position results when a change in inner pressure of the tank after starting movement of the body toward a valve opening direction becomes greater in magnitude than a predetermined amount, wherein the control unit stores the valve movement distance in the valve opening direction as a learning value, and also stores one of two predetermined restriction values as the learning value instead of the valve movement distance when the valve movement distance is not within a range between a previously stored learning value and one of the restriction values.