A machine tool having a column disposed on a base in a manner movable right and left as well as back and forth, a machine spindle unit disposed on the column in a manner movable upwardly and downwardly, plural grip arms gripping tools and being able to swing around arm shafts, a tool magazine making the plural grip arms circulate along a circulation pathway around a axis and a magazine drive section driving the tool magazine, wherein a tool gripped by the grip arm is exchanged to a tool of the machine spindle unit by an up and down movement of the machine spindle unit, comprising: a cover which covers the grip arms and the tool magazine, characterised in that: the cover comprises: an upper plate portion which is disposed on an upper side of the circulation pathway and has an opening at a center portion through which the machine spindle unit and the column can pass; an outer plate portion which extends to a lower side from an outer perimeter of the upper plate portion; an inner plate portion which extends to a lower side from an edge, excluding the magazine drive section's side and the machine spindle unit's side, among an inner perimeter of the upper plate portion; and a lower plate portion which extends to the lower side and the opening's side from a lower edge of the outer plate portion, the axis is inclined to the machine spindle unit's side with respect to a vertical line, and the lower plate portion positioned at the machine spindle unit's side includes a notch at a lower edge through which the grip arm can pass when the grip arm swings. a cover which covers the grip arms and the tool magazine, characterised in that: the cover comprises: an upper plate portion which is disposed on an upper side of the circulation pathway and has an opening at a center portion through which the machine spindle unit and the column can pass; an outer plate portion which extends to a lower side from an outer perimeter of the upper plate portion; an inner plate portion which extends to a lower side from an edge, excluding the magazine drive section's side and the machine spindle unit's side, among an inner perimeter of the upper plate portion; and a lower plate portion which extends to the lower side and the opening's side from a lower edge of the outer plate portion, the axis is inclined to the machine spindle unit's side with respect to a vertical line, and the lower plate portion positioned at the machine spindle unit's side includes a notch at a lower edge through which the grip arm can pass when the grip arm swings. the cover comprises: an upper plate portion which is disposed on an upper side of the circulation pathway and has an opening at a center portion through which the machine spindle unit and the column can pass; an outer plate portion which extends to a lower side from an outer perimeter of the upper plate portion; an inner plate portion which extends to a lower side from an edge, excluding the magazine drive section's side and the machine spindle unit's side, among an inner perimeter of the upper plate portion; and a lower plate portion which extends to the lower side and the opening's side from a lower edge of the outer plate portion, an upper plate portion which is disposed on an upper side of the circulation pathway and has an opening at a center portion through which the machine spindle unit and the column can pass; an outer plate portion which extends to a lower side from an outer perimeter of the upper plate portion; an inner plate portion which extends to a lower side from an edge, excluding the magazine drive section's side and the machine spindle unit's side, among an inner perimeter of the upper plate portion; and a lower plate portion which extends to the lower side and the opening's side from a lower edge of the outer plate portion, the axis is inclined to the machine spindle unit's side with respect to a vertical line, and the lower plate portion positioned at the machine spindle unit's side includes a notch at a lower edge through which the grip arm can pass when the grip arm swings.