Abstract: This disclosure relates to a punching apparatus for perforating sheet materials, and comprises a multiple tool holding unit mounted on a press table beneath a vertically movable press ram. The tool holding unit includes a horizontally extending upper arm having a horizontally swingably journalled holding member disposed at the free end thereof. The punch holding member is provided with a plurality of punch holding bores which may be selectively positioned beneath the press ram whereby holes of different diameter may be punched in the sheet material. The punching unit further includes a lower arm disposed beneath the horizontally extending upper arm, and includes a die holding bore having the configuration of two half circles connected with each other by two parallel lines running in the same horizontal direction as the lower arm and is further provided with a horizontally movable clamping member.