In a machine tool, a support member to which a headstock is mounted movably in an upward-downward direction is movable so as to change a position thereof in a horizontal direction relative to that of a bed. A guide member is provided on the bed and configured to guide the support member. An engageable portion at which the support member is supported by the guide member is located in the support member at a level within a range of upward-downward movement of the headstock along the support member.