To provide a method for drilling a hole in a pipe which can avoid the collapse of a hole drilling part, does not generate burrs and flash and chip and, in addition, can shorten the drilling time.

In this method for drilling a hole in a pipe, a front end face (13a) of a punch (13), to which voltage has been applied from a power source (14), is brought into contact with the surface of a pipe (11) to form a closed electric circuit. Next, while pushing the front end face (13a) of the punch into the pipe (11), the pipe (11) in its part in contact with the punch (13) is superheated by taking advantage of resistance heating upon the contact of the punch (13) with the pipe (11). The above contact part of the pipe (11) softened by the superheating is punched by the pressing force of the punch (13) to form a hole in the pipe (11).