An object of the present invention is to provide an implant structure assuring that substances accelerating breeding of bacteria are hard to be induced. The implant structure comprises: an artificial tooth root including an artificial tooth root main body having a distal end portion and a proximal end portion and a thread being formed at least on the distal end portion side and an induction portion for inducing a soft tissue provided on an outer periphery of the proximal end portion of the artificial tooth root main body and a support base having a covering portion at the proximal end portion side of the support base covering the whole surface of the proximal end portion side of the induction portion, wherein the support base is provided with a step portion along its outer periphery from the covering portion toward a distal end side of the support base.