A method for regenerating alveolar bone in which bone tissue is regenerated in the gap between an implant or dental root and alveolar bone, which comprises a procedure consisting of making an incision in the gingiva surrounding an implant or dental root embedded in alveolar bone, blowing a first air into the gap between the implant or dental root and the alveolar bone to remove a portion of infected granulation tissue present in the gap, and irradiating the gap with laser light to degenerate the infected granulation tissue remaining in the gap, followed by blowing a second air containing microparticles having calcium as a constituent thereof and water into the gap to remove the degenerated infected granulation tissue and fill in the gap with the wet microparticles.