A machine tool comprising: a spindle head for attaching a tool for processing a base material; a column configured to move the spindle head upward and downward by being mounted the spindle head at a front side; a saddle configured to move the column forward and rearward by being mounted the column at an upper side; a feed unit configured to move the saddle left and right by being mounted the saddle at an upper side; a table provided at one side of the feed unit and on which the base material to be processed by the spindle head is mounted; and a covering device configured to shield a non-processing region including the column, the saddle, and the feed unit from a processing region including the spindle head and the table, wherein the covering device includes: a rectangular main frame; a transfer frame which is mounted on upper and lower sides of the main frame and configured to be moved left and right; an opening and closing frame which is mounted on the transfer frame and configured to be moved upward and downward and through which the spindle head is exposed; and a curtain portion installed at the main frame, the transfer frame, the opening and closing frame, characterised in that: the opening and closing frame includes: a pair of lateral frames mounted on both surfaces of the transfer frame and configured to be moved upward and downward; an upper frame which is provided at upper ends of the pair of lateral frames; a cylinder which is provided on any one of the pair of lateral frames; and a lower frame configured to be separated from lower ends of the pair of lateral frames by the cylinder when the spindle head is moved from the processing region to the non-processing region or from the non-processing region to the processing region. a spindle head for attaching a tool for processing a base material; a column configured to move the spindle head upward and downward by being mounted the spindle head at a front side; a saddle configured to move the column forward and rearward by being mounted the column at an upper side; a feed unit configured to move the saddle left and right by being mounted the saddle at an upper side; a table provided at one side of the feed unit and on which the base material to be processed by the spindle head is mounted; and a covering device configured to shield a non-processing region including the column, the saddle, and the feed unit from a processing region including the spindle head and the table, wherein the covering device includes: a rectangular main frame; a transfer frame which is mounted on upper and lower sides of the main frame and configured to be moved left and right; an opening and closing frame which is mounted on the transfer frame and configured to be moved upward and downward and through which the spindle head is exposed; and a curtain portion installed at the main frame, the transfer frame, the opening and closing frame, a rectangular main frame; a transfer frame which is mounted on upper and lower sides of the main frame and configured to be moved left and right; an opening and closing frame which is mounted on the transfer frame and configured to be moved upward and downward and through which the spindle head is exposed; and a curtain portion installed at the main frame, the transfer frame, the opening and closing frame, characterised in that: the opening and closing frame includes: a pair of lateral frames mounted on both surfaces of the transfer frame and configured to be moved upward and downward; an upper frame which is provided at upper ends of the pair of lateral frames; a cylinder which is provided on any one of the pair of lateral frames; and a lower frame configured to be separated from lower ends of the pair of lateral frames by the cylinder when the spindle head is moved from the processing region to the non-processing region or from the non-processing region to the processing region. a pair of lateral frames mounted on both surfaces of the transfer frame and configured to be moved upward and downward; an upper frame which is provided at upper ends of the pair of lateral frames; a cylinder which is provided on any one of the pair of lateral frames; and a lower frame configured to be separated from lower ends of the pair of lateral frames by the cylinder when the spindle head is moved from the processing region to the non-processing region or from the non-processing region to the processing region.