A door keeper, for keeping a door opening angle of a door within a predetermined angle, includes a hinge bracket attached to a support structure; a keeper plate having a bracket side end portion pivotally mounted to the hinge bracket, a door side end portion, and a keeper guide slot having a door side slot end portion disposed proximate to the door side end portion of the keeper plate, the keeper guide slot extending from the door side slot end portion to an opposite slot end portion disposed at a location between the bracket side end portion and the door side end portion of the keeper plate; and a keeper member movably disposed in the keeper guide slot and fixedly attached to a lower part of the door. An opening motion of the door stops when the door side slot end portion engages the keeper member.