To provide a hole forming device capable of forming a through hole over a thick work regardless of size of a drill.

This device is equipped with a table 10 to which a work to be bored is fixed, and with paired boring tools 30 and 50 to be rotated around a shaft while the table is being held in between so as to let a hole be board. The boring tools 30 and 50 are coaxially provided while being faced to each other so as to be movable in an axial direction respectively. In addition, pressing parts 20 pressing the work so as to fix it onto the table 10, are provided for a frame 2, and a stopper plate for positioning the work can be mounted to the upper part of the table 10.