A mold holder device for a press brake comprising: a holder body , a mold clamp that clamps a mold (D) with respect to a mold contacting surface provided for the holder body of the mold holder device , the mold clamp being pivotally arranged on the holder body ; a long groove that being formed in a mold clamping surface with which the mold clamp clamps the mold (D) with respect to the mold contacting surface , the long groove being in parallel with a pivot axis of the mold clamp ; the mold holder device being characterized in that it further comprises: a metal pipe member having a longitudinal slit and being inserted in a rotation restricted state into the long groove such that turnings around an axial center in the long groove are restricted, a part of an outer peripheral surface of the pipe member being protruded toward the mold contacting surface , wherein the long groove has an opening on the mold clamping surface , a vertical dimension of the pipe member arranged in the long groove is greater than a vertical dimension of the opening and smaller than a distance between an upper surface and a lower surface of the long groove and a long-groove-depthwise dimension of the pipe member is greater than a dimension from the mold clamping surface of the mold clamp up to a depthwise wall surface of the long groove ; and the pipe member is divided into plural pieces. a holder body , a mold clamp that clamps a mold (D) with respect to a mold contacting surface provided for the holder body of the mold holder device , the mold clamp being pivotally arranged on the holder body ; a long groove that being formed in a mold clamping surface with which the mold clamp clamps the mold (D) with respect to the mold contacting surface , the long groove being in parallel with a pivot axis of the mold clamp ; the mold holder device being characterized in that it further comprises: a metal pipe member having a longitudinal slit and being inserted in a rotation restricted state into the long groove such that turnings around an axial center in the long groove are restricted, a part of an outer peripheral surface of the pipe member being protruded toward the mold contacting surface , wherein the long groove has an opening on the mold clamping surface , a vertical dimension of the pipe member arranged in the long groove is greater than a vertical dimension of the opening and smaller than a distance between an upper surface and a lower surface of the long groove and a long-groove-depthwise dimension of the pipe member is greater than a dimension from the mold clamping surface of the mold clamp up to a depthwise wall surface of the long groove ; and the pipe member is divided into plural pieces. a metal pipe member having a longitudinal slit and being inserted in a rotation restricted state into the long groove such that turnings around an axial center in the long groove are restricted, a part of an outer peripheral surface of the pipe member being protruded toward the mold contacting surface , wherein the long groove has an opening on the mold clamping surface , a vertical dimension of the pipe member arranged in the long groove is greater than a vertical dimension of the opening and smaller than a distance between an upper surface and a lower surface of the long groove and a long-groove-depthwise dimension of the pipe member is greater than a dimension from the mold clamping surface of the mold clamp up to a depthwise wall surface of the long groove ; and the pipe member is divided into plural pieces. <EOS>