A footwear includes a sole and a toe separating device disposed on a top surface of the sole. The toe separating device includes a hallux separating unit having a hallux separating column for separating the hallux and the second toe of a user's foot. The hallux separating column has a hallux columnar body defining a receiving space with an opening formed in a top surface thereof. The hallux columnar body has a length in a top-bottom direction and a width in a left-right direction transverse to the top-bottom direction. A hallux adjusting member is removably inserted into the receiving space through the opening to expand the width of the hallux columnar body.
