In the conventional alumina sintered bodies, a sintered body having high flexural strength, high toughness and high translucency in combination is not obtained, and a translucent alumina sintered body suitable for a dental material requiring both strength and sensuousness was not obtained. A translucent alumina sintered body having fracture toughness of 4.5 MPa·m0.5 or more, flexural strength of 350 MPa or more, and all light transmittance (sample thickness: 1 mm) to a visible light having a wavelength of 600 nm, of 60% or more is provided. The sintered body wherein sintered crystal grains are slender plate-like and/or columnar shape having an average aspect ratio of 1.5 or more and an average long axis length of 15 μm or less is preferred.