A horizontal lathe machine includes a work spindle unit disposed on a middle portion of a machine base and proximate to a front side of the machine base for holding a workpiece in an X-direction, and two tooling turret units located at two opposite sides of the spindle unit and driven to move in the X-direction by X-direction driving units. Each turret unit has a saddle movable on the machine base in the X-direction, and a turret driven by a turret driving member to rotate about a turret axis in a Y-direction that is perpendicular to the X-direction for facilitating a tool changing operation.

A horizontal lathe machine includes a work spindle unit disposed on a middle portion of a machine base and proximate to a front side of the machine base for holding a workpiece in an X-direction, and two tooling turret units located at two opposite sides of the spindle unit and driven to move in the X-direction by X-direction driving units. Each turret unit has a saddle movable on the machine base in the X-direction, and a turret driven by a turret driving member to rotate about a turret axis in a Y-direction that is perpendicular to the X-direction for facilitating a tool changing operation.

In a lathe equipped with a spindle for rotatably driving a work and a tool rest having a turret (rotary member) rotatably supporting a plurality of tools in an indexable manner about a horizontal axis, the tool rest is detachably installed on a tool rest installation portion formed so as to be positioned on an operator side so that the tools of the turret face the work side gripped by the spindle in an attachable and detachable manner.