Provided is an apparatus for manufacturing a single crystal, by which a single crystal having excellent qualities can be obtained with a relatively simple configuration. A method for manufacturing a single crystal, and a single crystal are also provided. In an apparatus (1) for manufacturing a single crystal, a raw material contained in a crucible (4) is melted with heat, and then a single crystal is manufactured by solidifying the material from one direction. The apparatus (1) is provided with an ampule (3), the crucible (4), a base (2) and a heater (5). The base (2) supports the ampule (3). The heater (5) is provided for the purpose of heating the ampule (3) and the crucible (4). The heat conductivity of the material configuring the base (2) is 0.5W/(mK) or more but not more than the value of the heat conductivity of the single crystal to be formed. As for the material configuring the base (2), the transmissivity of light at a wavelength of 1600 to 2400 nm is 10% or less when the material has a thickness of 4 mm.