In an apparatus for supporting drive of a mobile object, a curl component calculator projects relative motion of a environmental field in a coordinate system formed by modeling a retina sphere of a driver of the mobile object. The curl component calculator calculates each of rotational components of the projected relative motion of the environmental field around a corresponding driver's eye direction to the gaze point. A target trajectory setter sets, as a target trajectory of the mobile object, an equal-magnitude line connecting a part of the rotational components of the projected relative motion of the environmental field, the part of the rotational components having a same magnitude.