To speedily and certainly detect leakage of gas or liquid by a relatively simple inspection unit independent from a piping system of a semiconductor production apparatus even when piping for supplying or discharging with relatively less importance or risk on human bodies and environment.

The connection device 1 includes a pipe support 10 which has an easily breakable conductive part 11 and forms a continuity loop of the conductive part by supporting connected piping and a breakage detection part 20 which is electrically connected to the conductive part 11 and electrically detects a breakage of the conductive part 11 based on disconnection of the continuity loop.