A base of an inductor is provided. The inductor comprises an annular body, which has a hollow shaft portion and a surrounding sensing portion. The base comprises a bottom portion, a recess, and a hanging shelf. The recess is formed on the bottom portion. The hanger comprises a transverse shaft, disposed at the central portion of the hanging shelf and adapted to pass through the hollow shaft. When the lower portion of the hanging shelf is fixed in the recess, at least a portion of the peripheral induction portion of the annular body is adapted to rest in the recess.