An implant fixture that is inserted into a bone tissue formed of a cortical bone and a cancellous bone while rotating on a central axis to thereby form an artificial tooth root, the implant fixture including a first portion that is inserted into the cortical bone and includes a first screw thread having first peaks and first roots alternating with one another on an outer surface of the first portion; and a second portion that is disposed below the first portion and inserted into the cancellous bone.